GB2526278A

GB2526278A - Apparatus for generating sound

Info

Publication number: GB2526278A
Application number: GB1408814.0A
Authority: GB
Inventors: David John Skulina; Pasidu Pallawela; Benjaman Warren Schogler
Original assignee: SKOOGMUSIC Ltd
Current assignee: SKOOGMUSIC Ltd
Priority date: 2014-05-19
Filing date: 2014-05-19
Publication date: 2015-11-25
Anticipated expiration: 2034-05-19
Also published as: GB201408814D0; GB2526278B

Abstract

An apparatus 70 for generating sound comprises a resiliently deformable body 56, and a sensor arrangement such as a Hall Effect sensor and permanent magnet. The sensor arrangement comprises first and second sensor parts 84, 86 which are disposed such that the resiliently deformable body is operative upon deformation by a user to displace at least one of the first and second sensor parts relative to the other and is operative upon return from deformation to return the first and second sensor parts to substantially a same relative disposition that the first and second sensor parts had before deformation. The sensor arrangement generates a sensor output signal in dependence on displacement of at least one of the first and second sensor parts relative to the other, the sensor output signal corresponding to at least one sound. The sensor parts are preferably disposed on or within the resiliently deformable body, and may provide an electrical output which changes in dependence on a strength of a sensed magnetic flux density.

Description

Intellectual Property Office Application No. GB1408814.0 RTIVI Date:24 October 2014 The following terms are registered trade marks and should be read as such wherever they occur in this document: Zigbee Bluetooth Melexis Intellectual Property Office is an operating name of the Patent Office www.ipo.govuk

Title of Invention: Apparatus for generating sound

Field of the Invention

The present invention relates to apparatus for generating sound and in particular to apparatus for generating sound in dependence on actuation by a user, such as by manipulation of the apparatus by the user.

Background Art

Use of known sound generating apparatus such as musical instruments normally requires a fair degree of dexterity. Such known sound generating apparatus is therefore generally unsuited to use by persons with a wide range of physical, mental and behavioural disabilities as well as those who are inexperienced in playing or too young to play a musical instrument. GB 2479323 describes apparatus for generating sound which is more suited to use by such persons.

The apparatus of GB 2479323 is generally cuboid in form and comprises a resiliently deformable body which defines an outer surface of the apparatus. The apparatus of GB 2479323 further comprises an optical joystick arrangement which is supported within the deformable body and which is operative to sense deformation of the deformable body and provide a sensor output signal in dependence on deformation.

In one form the apparatus of GB 2479323 comprises a sound generating arrangement having a loudspeaker which is operative to emit sound in dependence on the sensor output signal. In another form the apparatus of GB 2479323 comprises a communications port which provides for conveying of the sensor output signal to the like of a Personal Computer comprising a sound generating arrangement. A user deforms the deformable body of the apparatus of GB 2479323 by, for example, pressing the exterior surface of the apparatus. The deformation is sensed by the optical joystick arrangement and the sound generating arrangement is operative to emit sound in dependence on the sensor output signal received from the optical joystick arrangement. The apparatus of GB 2479323 is configured to emit different tones in dependence on different kinds of deformation by, for example, pressing the exterior surface of the apparatus at different locations and by performing different twisting actions on the deformable body. A user can therefore perform a series of different manipulations of the deformable body to generate a corresponding series of different tones.

The present inventors have become appreciative of shortcomings of the apparatus of GB 2479323. It is therefore an object for the present invention to provide improved apparatus for generating sound in dependence on manipulation of the apparatus by a user.

Statement of Invention

The present invention has been devised in the light of the above mentioned appreciation of shortcomings of the apparatus of GB 2479323. According to a first aspect of the present invention there is therefore provided apparatus for generating sound comprising: a resiliently deformable body; and a sensor arrangement, the sensor arrangement comprising first and second sensor parts which are disposed such that the resiliently deformable body is operative upon deformation to displace at least one of the first and second sensor parts relative to the other and is operative upon return from deformation to return the first and second sensor parts to substantially a same relative disposition that the first and second sensor pads had before deformation, the sensor arrangement being operative to generate a sensor output signal in dependence on displacement of at least one of the first and second sensor pads relative to the other, the sensor output signal corresponding to at least one sound.

In use of the apparatus for generating sound, the resiliently deformable body is deformed such as by manipulation of the resiliently deformable body by a user. The sensor arrangement comprises first and second sensor parts which are disposed in the apparatus such that the resiliently deformable body is operative upon deformation to displace at least one of the first and second sensor pads relative to the other. The sensor arrangement is operative to generate a sensor output signal in dependence on displacement of at least one of the first and second sensor pads relative to the other, the sensor output signal corresponding to at least one sound.

The sensor output signal may therefore be provided to a sound generating arrangement which is operative to generate at least one sound in dependence on the sensor output signal. A user may thus deform the resiliently deformable body in each of a succession of different fashions which each provides for a different form of displacement of the first and second sensor parts which in turn provides for generation of a different sensor output signal. Each of plural different sensor output signals may provide for generation of a different sound. By way of example, the user may press the resiliently deformable body from one side to generate a first form of sound. According to another example, the user may twist the resiliently deformable body to generate a second form of sound. According to yet another example, the user may bend the top of the resiliently deformable body in relation to the bottom of the resiliently deformable body to generate a third form of sound.

Upon return from deformation, for example, when the user ceases manipulation of the resiliently deformable body, the resiliently deformable body is operative to return the first and second sensor pads to substantially a same relative disposition that the first and second sensor parts had before deformation. Return of the resiliently deformable body from deformation is unlikely to be instantaneous. Furthermore the resiliently deformable body may not return to its precise form before deformation in particular when material of the resiliently deformable body ages whereby the first and second sensor parts may not return to precisely a same relative disposition that the first and second sensor parts had before deformation. Nevertheless the resiliently deformable body returns substantially to its form before deformation whereby the first and second sensor pads return to substantially a same relative disposition that the first and second sensor pads had before deformation. There may be a drift over time of the relative disposition of the first and second sensor parts when the resiliently deformable body is un-deformed following many deformations of the resiliently deformable body.

The resiliently deformable body may define an exterior surface of sufficient surface area to permit direct manipulation by a user. The surface area may be sufficient to permit direct manipulation by at least a finger if not a hand of the user. The apparatus may comprise a cover formed of pliable material which fits over the resiliently deformable body. The cover may be thin such that it fits closely over the resiliently deformable body. A user may therefore not make direct contact with the exterior surface of the resiliently deformable body when manipulating the resiliently deformable body but when doing so may instead make direct contact with the cover.

Each of the first and second sensor parts may be one of disposed on and disposed within the resiliently deformable body. Where a sensor part is disposed on the resiliently deformable body, the sensor part may be at or at least near to an exterior surface of the resiliently deformable body. Where a sensor part is disposed within the resiliently deformable body the sensor part may be in the resiliently deformable body and may, for example, be held by material of the resiliently deformable body.

Alternatively the sensor part may be disposed within a space defined by the resiliently deformable body. More specifically the first and second sensor parts may be accommodated in the space.

The apparatus may be configured such that upon deformation an extent of change of relative disposition of the first and second sensor pads may be less than an extent of movement of the exterior surface of the resiliently deformable body such as is caused by manipulation by a user. At least one of the first and second sensor parts may therefore be disposed within the resiliently deformable body at a location spaced apart from the exterior surface. Material of the resiliently deformable body between part of the exterior surface which moves, for example in response to manipulation, and a sensor part may be operative to provide for a reduction in extent of movement of the sensor part compared with an extent of movement of the part of the exterior surface. The resiliently deformable body may therefore provide a compliant, i.e. non-rigid, mechanical coupling between the exterior surface and the sensor part. Where the mechanical coupling is compliant an extent of movement may be reduced by compression of the resiliently deformable body when the movement of the exterior surface is in one direction and by stretching of the resiliently deformable body when the movement of the exterior surface is in a second, opposite direction. The apparatus may be configured such that a force applied at the exterior surface, such as by manipulation by a user, is mechanically coupled to at least one of the first and second sensor parts by way of solely one path, the path comprising the resiliently deformable body and more specifically where the path follows solely one direction.

The apparatus for generating sound may be configured such that displacement of the first and second sensor parts relative each other comprises movement of at least one of the first and second parts relative to the other in each of at least two perpendicular directions. More specifically displacement may comprise movement of at least one of the first and second parts relative to the other in each of at least three mutually perpendicular directions. Movement in each of at least two perpendicular directions may comprise linear translation of at least one the first and second sensor parts. Movement of a sensor part in a direction may therefore be bodily such that all of the sensor part moves in the direction to a same extent. In other words movement may be such that the sensor part substantially maintains orientation in relation to the at least two perpendicular directions even though the sensor part may be supported such that it is capable of a change of orientation. The sensor arrangement may be configured to provide for determination of deformations further to deformation along each of three perpendicular axes. More specifically the sensor arrangement may provide for determination of deformation involving rotation about at least one axis and perhaps about three mutually perpendicular axes. The apparatus for generating sound may thus be capable of responding to varied and complex deformations of the resiliently deformable body.

The first and second sensor parts may be operative of themselves to sense movement in each of at least two perpendicular directions and more specifically each of three mutually perpendicular directions. There may therefore be no need for plural pairs of sensor parts for sensing of movement in a respective one of plural perpendicular directions.

In certain forms, the sensor arrangement may comprise plural pairs of first and second sensor parts, such as plural pairs of magnets and Hall Effect sensors.

Having plural pairs of first and second sensor parts may provide for an improvement in sensing of more complex deformations, such as compression of opposing sides of the resiliently deformable body or translation and rotation of the top of the resiliently deformable body in relation to the bottom of the resiliently deformable body. The plural pairs of first and second sensor parts may be at least one of disposed differently and configured differently. The plural pairs of first and second sensor parts may be disposed differently in respect of at least one of location and orientation. The plural pairs of first and second sensor parts may be configured differently, aside from where they are disposed, in respect of differing responses to a particular direction of deformation. The plural pairs of first and second sensor parts may therefore be operative to sense a different direction of deformation or to sense a particular form of deformation differently.

The apparatus for generating sound may be configured such that the first sensor parts of the plural pairs may describe a same path of displacement in dependence on deformation of the resiliently deformable body. For example, the first sensor parts of the plural pairs may be rigidly coupled to each other, such as by way of their mounting on a rigid member. Alternatively or in addition the apparatus for generating sound may be configured such that the first sensor parts move independently of each other. The first sensor parts may therefore describe different paths of displacement in dependence on deformation of the resiliently deformable body. The apparatus for generating sound may be configured such that there is no rigid coupling between different ones of the first sensor parts. More specifically, coupling between different ones of the first sensor parts may be by way of the resiliently deformable body and perhaps such that the resiliently deformable body may be the only coupling between different ones of the first sensor parts for at least part of a path between the different ones of the first sensor parts.

The sensor arrangement may be operative to process a signal from each of the pairs of first and second sensor parts independently. For example the sensor arrangement may be operative to process a first signal from a first pair and a second signal from a second pair independently of each other, the first and second signals providing more information than is yielded by one of the first and second signals alone. Alternatively or in addition the sensor arrangement may be operative to process signals from the pairs of first and second sensor parts in combination. For example where there are three pairs of first and second sensor parts which are disposed appropriately, the sensor arrangement may be operative to perform a triangulation operation based on first to third sensor signals from respective first to third pairs.

The sensor arrangement may be operative to generate the sensor output signal on an electromagnetic basis. More specifically the sensor arrangement may be configured to provide an electrical output which changes in dependence on a strength of a sensed magnetic field and more specifically magnetic flux density. The sensor arrangement may therefore comprise a Hall Effect sensor arrangement in which the first sensor part comprises a permanent magnet and the second sensor part comprises a Hall Effect sensor. The Hall Effect sensor may be configured to sense magnetic field strength in each of three mutually perpendicular directions.

The magnet may be axially magnetised. The magnet may be in the form of a rod.

An axially magnetised rod magnet may produce a symmetric magnetic field which may be advantageous for determination of magnetic field strength. The apparatus for generating sound may be configured such that the first only of the first and second sensor pads may move in dependence on deformation of the resiliently deformable body. Where the apparatus comprises a Hall Effect sensor, the first sensor part may comprise a magnet. The Hall Effect sensor may be disposed such that its top surface is substantially parallel to a pole surface of the magnet.

In an embodiment, the sensor apparatus may comprise a third sensor part which may be disposed at a spaced apart location from the second sensor part, the apparatus for generating sound being configured to sense displacement of the first and second sensor parts relative each other and displacement of the first and third sensor parts relative each other. Where the first sensor part comprises a magnet and the second sensor part comprises a Hall Effect sensor, the third sensor part may comprise a further, i.e. second, Hall Effect sensor. The second Hall Effect sensor may be configured to sense magnetic field strength in each of three mutually perpendicular directions. The second Hall Effect sensor may be disposed such that its top surface is substantially perpendicular to a pole surface of the magnet.

Alternatively or in addition and where the resiliently deformable body defines two parallel and oppositely directed exterior surfaces, the second Hall Effect sensor may be disposed such that its top surface is substantially parallel to the oppositely directed exterior surfaces.

As mentioned above, the apparatus for generating sound may be configured to generate sound, for example, by providing a sensor output signal to a sound generating arrangement which is operative to generate at least one sound in dependence on the received sensor output signal. The apparatus for generating sound may therefore further comprise a sound generating arrangement which, for example, comprises a loudspeaker. In one embodiment the sound generating arrangement may be comprised in a unitary arrangement which also comprises the resiliently deformable body. In another embodiment the sound generating arrangement may be apart from, i.e. not comprised in, a unitary arrangement comprising the resiliently deformable body. More specifically the sound generating arrangement may, for example, be comprised in the like of a Personal Computer.

The apparatus for generating sound may therefore comprise further apparatus such as a PC, the further apparatus comprising the sound generating arrangement.

Alternatively or in addition the apparatus for generating sound may comprise communications apparatus which is configured to provide for a signal corresponding to the sensor output signal to be conveyed to the like of a Personal Computer. The communications apparatus may be configured to provide for at least one of wired and wireless communication of the signal corresponding to the sensor output signal.

Where transmission is wired the unitary arrangement may comprise an electrical connector, such as a LJSB socket. Where transmission is wireless the unitary arrangement may comprise a wireless transmitter which is operative according to the like of the Zigbee protocol, the Bluetooth protocol or a custom defined protocol. A custom defined protocol may offer the advantage over proprietary protocols of lower processor overhead and reduced latency times. The design of a custom defined protocol will be within the ordinary design capabilities of the person skilled in the art.

Determination of displacement of the first and second sensor parts may be achieved by way of digital processing. The apparatus for generating sound may further comprise processing apparatus. The processing apparatus may comprise analogue-to-digital conversion apparatus which is operative to receive an analogue signal from the sensor arrangement and provide a corresponding digital signal. The analogue-to-digital conversion apparatus may be operative to sample from the sensor apparatus at a rate of no less than 1 kHz. The processing apparatus may further comprise a digital processor, such as may be comprised in a microprocessor or a digital signal processor, which is operative to receive the corresponding digital signals and a make a displacement determination in dependence thereon. The microprocessor and perhaps further features of the processing apparatus such as the filter described below may be comprised in a general purpose computer such as a Personal Computer. The processing apparatus may be configured to determine a direction of displacement of the first and second sensor parts in relation to each other in dependence on an output signal from the sensor arrangement. Alternatively or in addition the processing apparatus may be configured to determine an extent of displacement of the first and second sensor parts in relation to each other.

In apparatus which is configured to sense displacement in three dimensions and thereby provide a measurement for each dimension, the processing apparatus may be operative to determine each of three quantities on the basis of a respective one of the three measurements. Each measurement may, for example, be a voltage generated by the sensor arrangement. Where the sensor arrangement is operative on an electromagnetic basis, each of the three quantities may comprise magnetic flux density. The three quantities may, for example, be magnetic flux density along notional x, y and z axes. The processing apparatus may be operative to determine two different ratios of pairs of three quantities, such as ratios of pairs of magnetic flux density along notional x, y and z axes. The processing apparatus may be operative to make a determination in respect of deformation of the resiliently deformable body in dependence on the two different ratios. Making a determination in respect of deformation in dependence on the ratios may offer the advantage over the making of a determination in dependence on the measurements or quantities themselves of reducing the effect of ageing or temperature change.

Different forms of deformation may be characterised by different patterns of measured quantities or patterns of ratios of measured quantities. For example deformation involving depressing the resiliently deformable body on a first side may provide a first pattern, deformation involving depressing the resiliently deformable body on a second oppositely directed side may provide a second pattern and deformation involving twisting the resiliently deformable body may provide a third pattern. The processing apparatus may therefore be configured to perform pattern recognition on quantities based on sensor output signals generated by the sensor arrangement. The processing apparatus may comprise comparative patterns stored in the apparatus for generating sound. Pattern recognition may comprise comparison of the quantities with the comparative patterns. The comparative patterns may be acquired and stored during the like of a post-manufacture or calibration process during which the resiliently deformable body is deformed in each of plural known fashions. Alternatively each comparative pattern may be reduced to a set of rules and the set of rules stored in the processing apparatus for a subsequent rule based comparison process.

The processing apparatus may be configured to determine a direction of a deformation. For example where the deformation involves displacement in a notional X direction, the processing apparatus may be configured to determine that the displacement in the X direction is of a positive or negative nature. The processing apparatus may be operative to determine the direction of deformation after determination of the form of the deformation. Where the processing apparatus is operative to determine an extent (i.e. magnitude) deformation, the extent may be determined after determination of the direction of deformation.

The processing apparatus may be configured to provide for self-calibration of the apparatus for generating sound. As described above the resiliently deformable body normally returns to its original shape or near its original shape after deformation with the latter circumstance tending to arise after more prolonged use. It may not be important for proper functioning of the apparatus for generating sound for the change in displacement to be related to the original locations of the first and second sensor parts with it being merely sufficient for the displacement to involve a change from a current un-deformed condition. The processing apparatus may therefore be operative in dependence on an output signal from the sensor arrangement when the resiliently deformable body is un-deformed and use such measurement as a reference basis to determine the change of displacement when the resiliently deformable body is subsequently deformed.

The resiliently deformable body may comprise gaseous voids. The resiliently deformable body may comprise a polymer such as polyurethane which may be in the form of a foam, such as from Urofoam Ltd. of Duddon Road, Askam-in-Furness, Cumbria LA16 7AN, United Kingdom. The resiliently deformable body may be unitary. The resiliently deformable body may, for example, be formed from one mass of resilient material. Alternatively the resiliently deformable body may comprise plural resiliently deformable components which are disposed such that they abut each other.

The resiliently deformable body may be configured to be deformable along at least two orthogonal directions and more specifically along three mutually orthogonal directions. Alternatively or in addition the resiliently deformable body may be configured to be deformable around at least two orthogonal axes and more specifically around three mutually orthogonal axes.

The resiliently deformable body may define a polyhedron. More specifically the resiliently deformable body may be generally and more specifically substantially cuboid in form. Alternatively the resiliently deformable body may be of more rounded form and may, for example, be spherical or cylindrical. The resiliently deformable body may have an exterior surface profile which defines plural areas which are intended to be pressed by a user. The plural areas may be defined by way of the like of protrusions or recesses. As mentioned above, the resiliently deformable body may define a space. The space may accommodate electronic apparatus such as at least one component of processing apparatus.

The processing apparatus may comprise a filter which is operative to filter signals received from the sensor arrangement. The filter may be configured to reduce noise such as 50 Hz noise. Alternatively or in addition the filter may be configured to reduce a response arising from a slow return of the resiliently deformable body from deformation. The resiliently deformable body may rebound to a large extent relatively quickly followed by a more extended period during which the resiliently deformable body finally recovers its original shape or near its original shape. The filter may therefore comprise a high pass filter which is operative to reduce a response arising from a slow return of the resiliently deformable body from deformation.

The apparatus for generating sound may further comprise audio apparatus which is operative in dependence on a signal generated by the sensor arrangement. More specifically the audio apparatus may be operative in dependence on a signal received from the processing apparatus. The audio apparatus may comprise sound emitting apparatus such as a loudspeaker. Alternatively or in addition the audio apparatus may comprise an audio synthesiser.

The apparatus for generating sound may comprise a power source which is operative to provide electrical power to, for example, the sensor arrangement. The power source may comprise a battery. Alternatively or in addition the power source may comprise a connector arrangement for receiving electrical power from an external source such as a mains transformer arrangement. Where the processing apparatus is unitary with the resiliently deformable body and the apparatus for generating sound is battery power driven the processing apparatus may be configured such that at least one component of the processing apparatus is operative to enter a power down state involving reduced power consumption. The processing apparatus may be operative to enter the power down state where a signal received from the sensor arrangement indicates there is substantially no displacement of the first and second sensor parts in relation to each other. More specifically the processing apparatus may be operative to enter the power down state when there has been no such displacement for a predetermined period of time, such as five minutes.

In an embodiment at least some of the processing apparatus may be spaced apart from a unitary arrangement comprising the resiliently deformable body. It may therefore be necessary to convey signals from the unitary arrangement for processing of signals. The unitary arrangement may therefore comprise a signal transmission arrangement which is operative to provide for at least one of wired and wireless transmission of signals from the unitary arrangement. Where transmission is wired the unitary arrangement may comprise an electrical connector, such as a LJSB socket. Where transmission is wireless the unitary arrangement may comprise a wireless transmitter which is operative according to the like of the Zigbee protocol, the Bluetooth protocol or a custom defined protocol.

Although the apparatus described above is operative for the production of sound, the apparatus may in addition be configured for use in fields other than sound production. Gaming, computer aided design and process control constitutes a non-exhaustive list of additional applications of the apparatus for sound generation of the present invention.

According to a second aspect of the present invention there is provided sound generating apparatus comprising apparatus for generating sound according to the first aspect of the present invention and audio apparatus, such as a loudspeaker, which is operative to emit sound in dependence on a signal received from the apparatus for generating sound. Embodiments of the second aspect of the present invention may comprise one or more features of the first aspect of the present invention such as the processing apparatus and features thereof.

The sound generating apparatus may comprise plural apparatus for generating sound which are each configured and operative as described above with reference to the first aspect of the present invention. Processing apparatus of the sound generating apparatus may be configured to be operative in dependence on signals from the plural apparatus for generating sound. The audio apparatus may be operative to, for example, emit sound in dependence on signals from the plural apparatus for generating sound. Each of several users may thus manipulate his or her apparatus for generating sound, with the audio apparatus being operative to emit sound in dependence on manipulation of all the apparatus for generating sound.

According to a further aspect of the present invention there is provided apparatus for generating sound comprising: a resiliently deformable body; and a sensor arrangement, the sensor arrangement comprising first and second sensor parts which are disposed such that the resiliently deformable body is operative upon deformation to displace at least one of the first and second sensor parts relative to the other. The sensor arrangement may be operative to generate a sensor output signal in dependence on displacement of at least one of the first and second sensor parts relative to the other, the sensor output signal corresponding to at least one sound. Further embodiments of the further aspect of the present invention may comprise one or more features of any previous aspect of the present invention.

Brief Description of Drawings

Further features and advantages of the present invention will become apparent from the following specific description, which is given by way of example only and with reference to the accompanying drawings] in which: Figure 1A is a block diagram representation of a first embodiment of sound generating apparatus; Figure 1 B is a block diagram representation of a second embodiment of sound generating apparatus; Figure 2 provides a side view of apparatus for generating sound according to an embodiment of the present invention; Figure 3 is a sectional view through the apparatus of Figure 2; Figure 4 shows traces of variables obtained in response to a first form of deformation; Figure 5 shows traces of derivatives of variables obtained in response to the first form of deformation; Figure 6 shows traces of variables obtained in response to a second form of deformation; Figure 7 shows traces of derivatives of variables obtained in response to the second form of deformation; Figure 8 shows traces of variables obtained in response to a third form of deformation; Figure 9 shows traces of derivatives of variables obtained in response to the third form of deformation; and Figure 10 shows an alternative configuration of sensors to the configuration shown in Figure 3.

Description of Embodiments

A block diagram representation of a first embodiment of sound generating apparatus is shown in Figure 1A. The sound generating apparatus 10 of Figure 1A comprises a unitary arrangement 12 which comprises apparatus for generating sound 14 and processing apparatus 16. The sound generating apparatus 10 further comprises a Personal Computer 18 having a loudspeaker whereby the Personal Computer 18 can emit sound in dependence on signals received from the unitary arrangement 12. The form and function of the apparatus for generating sound 14 is described below with reference to Figure 2 and the apparatus for generating sound 14 and the processing apparatus 16 are described below with reference to Figure 3.

The unitary arrangement 12 is spaced apart from the Personal Computer 18 albeit a shod distance apart whereby sounds emitted by the Personal Computer 18 in dependence on manipulation of the apparatus for generating sound 14 by a user can be heard by the user. Each of the unitary arrangement 12 and the Personal Computer 18 comprises a communications arrangement which is operative to provide for either wired or wireless communication between the unitary arrangement 12 and the Personal Computer 18. Where the communications arrangements provide for wired communication the communications arrangements comprise a USB socket and known support circuitry. Where the communications arrangements provide for wireless communication the communications arrangements comprise a wireless transceiver, such as a transceiver configured to operate in accordance with the Zigbee protocol, the Bluetooth protocol, or a custom defined protocol. The design of a transceiver of such form will be familiar to the skilled reader and will therefore be described no further. The Personal Computer 18 is configured to receive signals from each of several unitary arrangements 12 with the Personal Computer 18 being operative to process such signals and to emit sound in dependence on the processed signals. Several users may thus manipulate their own apparatus for generating sound and thereby produce sound by way of a single Personal Computer 18.

A block diagram representation of a second embodiment of sound generating apparatus 30 is shown in Figure 1 B. The sound generating apparatus 30 comprises a unitary arrangement 32 which comprises apparatus for generating sound 34, processing apparatus 36 and sound emitting apparatus 38. The sound emitting apparatus 38 comprises a loudspeaker whereby the sound emitting apparatus 38 can emit sound in dependence on signals received from the processing apparatus 36. There is therefore no need for the Personal Computer 18 of the embodiment of Figure lAfor production of sound in dependence on manipulation of the apparatus for generating sound 34 by a user. The unitary arrangement 32 is thus capable of stand-alone operation. In certain forms of this embodiment, the sound emitting apparatus 38 comprises a communications arrangement which is operative to provide for either wired or wireless communication. The communications arrangement is of the same form and function as described above with reference to Figure 1A. The communications arrangement provides for communication with further (un-illustrated) apparatus such as a Personal Computer configured to operate as an audio synthesiser or a specifically designed audio synthesiser to provide for more complex audio processing than may be provided by the processing apparatus 36 comprised in the unitary arrangement 32. The form and function of the apparatus for generating sound 34 is described below with reference to Figure 2 and the apparatus for generating sound 34 and the processing apparatus 36 are described below with reference to Figure 3.

In further embodiments of sound generating apparatus components of the processing apparatus 16, 36 can be split between the unitary apparatus 12, 32 and spaced apart apparatus such as a Personal Computer or an audio synthesiser in a manner other than those represented in Figures 1A and 1 B. According to one example, interface circuits of the apparatus for generating sound and analogue-to-digital conversion circuitry is comprised in the unitary arrangement and signal processing circuitry is comprised in the Personal Computer or the audio synthesiser.

A side view of apparatus for generating sound 50 according to an embodiment of the present invention is shown in Figure 2. The apparatus for generating sound 50 is of generally cuboid form and defines a substantially planar surface 52 on which the apparatus for generating sound 50 is supported on a table, a floor or the like. Each of the remaining five surfaces defines a part-spherical protrusion 54 with each protrusion being differently coloured. The protrusions 54 indicate where a user should press the apparatus for generating sound 50 to provide for sound production and provide on account of their shape and colour for ease of visual perception. It should be noted, however, that manipulation of the apparatus for generating sound at locations and in fashions which involve other than the application of pressure directly at the protrusions 54 provide for sound production. The apparatus for generating sound 50 comprises a main body 56 and a base portion 58, which defines the substantially planar surface 52 on which the apparatus for generating sound 50 is supported. The main body 54 comprises a resiliently deformable body in the form of a cube of dimensions of 40 mm by 40 mm by 40 mm. The resiliently deformable body is formed from polyurethane foam from Urofoam Ltd. of Duddon Road, Askam-in-Furness, Cumbria LA16 7AN, United Kingdom. The resiliently deformable body is covered with a skin of hard-wearing and readily cleaned material.

The base portion 58 defines a hollow rectangular space in which components of the processing apparatus are contained. In one form, the base portion 58 comprises a hollow plastics body and a skin of foam material with the resiliently deformable body being adhered to the upper surface of the hollow plastics body. In another form, the base portion 58 is integrally formed with the resiliently deformable body 56.

According to this form, the resiliently deformable body 56 is hollowed out at its lower end and a rectangular plastics case is located in the hollowed out space to hold and protect the components of the processing apparatus. Where communication with external apparatus such as a Personal Computer is wired, an electrical connector such as a USB socket is provided in the side of the base portion 58.

A sectional view 70 through the apparatus of Figure 2 is shown in Figure 3.

Components of the apparatus shown in Figure 3 in common with the apparatus shown in Figure 2 are designated by like reference numerals. Different but by no means all of the deformations which the resiliently deformable body 56 is liable to undergo are indicated by arrows. A first arrow 72 indicates the pressing of the protrusion 54 on the right hand side of the apparatus 70. A second arrow 74 indicates the pressing of the protrusion 54 on the left hand side of the apparatus 70.

A third arrow 76 indicates the pressing of the protrusion 54 on the top of the apparatus 70. A fifth arrow 78 which extends around the first arrow 72 indicates pitching of the upper end of the apparatus in relation to the base portion 58 or more specifically rotation of the upper end of the apparatus in relation to the base portion 58 about an axis which extends between the left and right protrusions 54. A sixth arrow 80 indicates rolling of the upper end of the apparatus in relation to the base portion 58 or more specifically rotation of the upper end of the apparatus in relation to the base portion 58 about an axis which extends between the rear and front protrusions 54. The sound generating apparatus 10, 30 is configured to generate a different sound in dependence on each of the indicated deformations.

As can be seen from Figure 3, the resiliently deformable body 56 defines an internal space 82 of cuboid form immediately above the base portion 58. An axially magnetised short rod magnet 84 (which constitutes a first sensor part of a sensor arrangement) is attached to the roof of the internal space 82. A first Melexis MLX 90333 3D Hall Effect sensor 86 (which constitutes a second sensor part of a sensor arrangement) from Future Electronics of Future House, The Glanty, Egham, Surrey, United Kingdom is mounted immediately below the rod magnet 84 within the internal space 82. A second Melexis MLX 90333 3D Hall Effect sensor 88 (which constitutes a third sensor part of a sensor arrangement) is mounted below and to one side of the rod magnet 84 within the internal space 82. Each of the two Hall Effect sensors 86, 88 is surface mounted on its own printed circuit board 90. Each printed circuit board comprises signal conditioning and interface circuitry for its respective Hall Effect sensor. Although not shown in Figure 3 the printed circuit boards 90 are enclosed by a cover formed of rigid plastics material to provide protection for the Hall Effect sensors 86, 88 and circuitry on the printed circuit boards 90 from impact from the magnet 84 in the event that the resiliently deformable body 56 is subject to extreme deformation. The first Hall Effect sensor 86 is located such that its top surface is substantially parallel to a pole surface of the magnet. The second Hall Effect sensor 88 is disposed such that its top surface is substantially perpendicular to a pole surface of the magnet and oppositely directed exterior surfaces of the resiliently deformable body. As can be appreciated from Figure 3 deformation of the resiliently deformable body 56 results in movement of the magnet 84 in relation to the two Hall Effect sensors 86, 88 in at least one of three mutually perpendicular directions.

As is mentioned above the processing apparatus is contained within the base portion 58. As is described in more detail below each printed circuit board 90 is operative to generate a voltage signal which changes in dependence on movement of the magnet 84 in relation to the Hall Effect sensor mounted on the printed circuit board 90. The processing apparatus comprises a 12-bit analogue-to-digital converter which is operative to acquire signals from the Hall Effect sensors 86, 88 and to convert the acquired signals to digital form. The analogue-to-digital converter is operative to sample from the Hall Effect sensors 86, 88 at a rate of no less than 1 kHz. Following analogue-to-digital conversion, the processing apparatus is operative to filter the acquired digital signals to reduce the like of 50 Hz noise. A filter comprised in the processing apparatus is further operative on a high pass basis to reduce low frequency signals arising from the latter stage of the resiliently deformable body returning to its undeformed state following deformation. Although not shown in Figure 3 the processing apparatus comprises the like of power supply regulation circuitry and level shift circuitry to provide for proper matching of signal levels to digital circuitry. The design of such circuitry is considered to be within the ordinary design capabilities of the skilled reader and is therefore described no further.

Considering operation of the magnet 84 and a Hall Effect sensor 86, 88 further, for an axially magnetised rod magnet of radius R and thickness T (i.e. in a direction along the magnet perpendicular to the radius) having a magnetic flux density B. at its surface, the magnetic flux density B at a distance X from the mid-point of the front surface of the magnet is given by: Br X+T X 8=5 (1) [(x + T)2 + R2]2 [R2 + X2]2 Each of the two Hall Effect sensors 86, 88 is operative to measure the magnetic flux density of the magnet in each of X, Y and Z directions such that one has B, B and B1 for each of the two Hall Effect sensors 86, 88 with each Hall Effect sensor generating voltages V, V,, and V corresponding respectively to the magnetic flux densities B, B and B1. B, B and B are therefore given by the following three equations:

KV KV

= cos (atan * sin (atan) (2) VX Vy

KV ___

By = sin (atan) * cos (atan) (3) "TX vy

KV KV

= sin (atan * sin (atan) (4) Vx Vy In the above three equations K is a constant which is chosen to provide a desired scaling of the voltage ratios. According to a first approach, movement of the magnet 84 is determined on the basis of B, B and B1 as calculated with the above equations. According to a second approach, ratios between flux densities in different directions for each Hall Effect sensor, for example B11IB1 and B11IB1 for the first Hall Effect sensor, are used instead to determine magnet movement with this approach providing compensation for ageing and temperature drift.

According to the second approach the processing apparatus is then operative to determine the following variables where the suffix 1' indicates the first Hall Effect sensor and the suffix 2' indicates the second Hall Effect sensor: AD = Arctan- Al = Arctan- A2 = Arctan- A3 = Arctan-Thereafter the processing apparatus is operative to determine the following variables:

AO

ii. Al iii. A2 iv. A3 v. AO+A1 vi. AO-Al vU. A2+A3 vUi. A2-A3 ix. AO/Al x. AO/A2 xi. AO/A3 xii. Al/A2 xiii. Al/A3 xiv. A2/A3 xv. AU/Al + A0/A2 xvi. AU/Al + A0/A3 xvh. AU/Al +A1/A2 xviii. A1/A2+Al/A3 xix. A2/A3 + Al/A3 xx. AU/Al + A0/A2 xxi. Time domain derivatives of the above variables, e.g. d[(AO/A1)]Idt Thereafter the processing apparatus is operative to determine the form of deformation on the basis of variables i. to xxi. in respect of direction of movement of surfaces of the resiliently deformable body by way of a fuzzy pattern recognition and/or fuzzy rule based approach. A library of reference patterns and/or rules is formed during a post-manufacture or calibration phase, during which the resiliently deformable body is deformed in each of several predetermined fashions, the processing apparatus is operative to determine the above variables for each deformation and the variables are analysed to determine a characteristic pattern or a rule for each form of deformation. A library of reference patterns and/or rules is formed by storing a characteristic pattern and/or rule for each form of deformation.

Thereafter during use of the apparatus for generating sound the measured variables are subject to a pattern recognition process involving comparison on a fuzzy basis with the reference patterns or rules in the library to determine the present form of deformation. Several examples of characteristic patterns will now be provided.

Figure 4 shows the change over time of variables when the resiliently deformable body 70 of Figure 3 is subject to deformation along direction 76 by pressing of its top surface on three occasions. As can be seen certain variables, such as A1/A0 and A2-A3, are negative and other variables, such as A3/A0, AU/A2 and A2/A3, have amplitudes which vary between 0 and 1, and yet other variables have amplitudes which vary above 1. These patterns of behaviour are reduced to a set of rules which are stored in the processing apparatus for subsequent use. In addition one of the variables, i.e. AO + Al, exhibits an appreciably higher rate of change than the other variables. Therefore the derivative of AU + Al is also stored as a library pattern in the processing apparatus for subsequent use on a pattern recognition basis to provide an additional or alternative means of recognising this form of deformation.

The use of derivatives is further described with reference to Figure 5. Figure 5 shows the derivative behaviour of some of the variables. As can be seen from Figure 5 one of the traces, i.e. the derivative of A0 + Al, exhibits a markedly different behaviour from the other derivatives whereby a derivative pattern can be used to recognise this form of deformation.

Figure 6 shows the change over time of variables when the resiliently deformable body 70 of Figure 3 is subject to deformation along direction 72 by pressing of the right hand side surface on three occasions. As can be seen certain variables, such as A2, AOIA1 and A2+A3 undergo characteristic change. As described above with reference to Figure 4 a set of fuzzy rules is determined by analysis of how such variables vary overtime. Alternatively or in addition, derivative behaviour is used to determine that the rate of change of each of AO/A2, AOIA1 and A0+A1 is markedly greater than the rates of change of the other variables. The derivative behaviour is shown in Figure 7. The derivative behaviour is stored as a library pattern for subsequent use during a pattern recognition process.

Figure 8 shows the change over time of variables when the resiliently deformable body 70 of Figure 3 is subject to a pitching movement as indicated by reference numeral 78. As can be seen from Figure 8 certain variables, such as A1/A0 and A2-AS, are negative and other variables, such as A3 and A2/A3, have amplitudes which vary between 0 and 1, and yet other variables have amplitudes which vary above 1.

As described above these patterns of behaviour are reduced to a set of rules which are stored in the processing apparatus for subsequent use. It should be noted that some of the variables in Figure 8 go to infinity on account of zero crossings. Such behaviour is avoided by way of an algorithm which is operative to detect when a variable is approaching zero. When a zero approaching variable is detected a small, predetermined offset is applied to the variable to thereby avoid a variable going to infinity and assist the processing apparatus in determining that the variable has reached infinity. Alternatively or in addition, derivative behaviour is used to determine that the rate of change of each ofAl/A3, A1/A2 and AOIA3 is markedly greater than the rates of change of the other variables. The derivative behaviour is shown in Figure 9 which shows three successive pitching deformations of the same form as for Figure 8. The derivative behaviour is stored as a library pattern for subsequent use during a pattern recognition process. Derivative behaviour has been found to be particularly useful for identifying deformations involving rotation such as pitching, yawing, rolling and diagonal twisting.

After the form of deformation is determined, i.e. X direction, Y direction, 7 direction, roll, pitch or yaw, the processing apparatus is then operative to determine the direction of the deformation, for example X+ direction, X-direction, Y+ direction, etc. Thereafter the processing apparatus is operative to determine an extent (or amplitude) of deformation in dependence on the amplitudes of the flux density changes.

The processing apparatus is operative to match forms of deformation, directions and extents of deformation with particular tones or combinations of tones which are then emitted by a loudspeaker comprised in the sound generating apparatus. As described above, the forms, directions and extents of deformation are reflected by movement of the magnet which arises from a user pressing one or more sides of the resiliently deformable body at a particular time and performing more complex manipulations of the resiliently deformable body such as compressing the whole body, bending the top of the body around one or more of three mutually orthogonal axes and shearing the top of the body along one or both of the x and y axes with respect to the base portion of the apparatus for generating sound. As mentioned above the sound generating apparatus comprises an audio synthesiser. The audio synthesiser is operative on signals received from the processing apparatus to provide for specific effects, such as a woodwind or stringed instrument effect. The sound generating apparatus can therefore be configured to operate as a musical instrument.

The apparatus for generating sound is configured to respond to the application of deformation causing pressures having a weight in the range of ig to 5000g. The apparatus is configured to measure magnet displacement to an accuracy of +-1% and to measure deformation of the resiliently deformable body material to within ---1 mm. During use the apparatus for generating sound is operative to perform self-calibration involving measurement and storage of magnet position when there is no deformation of the resiliently deformable body to establish a fresh baseline for subsequent measurements. During subsequent use of the apparatus for generating sound measurements made during deformation of the resiliently deformable body are referred to stored measurements.

As is described above the embodiment of Figure 3 comprises two Hall Effect sensors 86, 88 and a magnet 84. An alternative configuration of sensors is represented in Figure 10. The configuration of Figure 10 comprises a first magnet 100 and a first pair of Hall Effect sensors 102, a second magnet 104 and a second pair of Hall Effect sensors 106 and a third magnet 108 and a third pair of Hall Effect sensors 110. The first magnet 100 is disposed relative to the first pair of Hall Effect sensors 102 such that that they are operative together to sense relative displacement in each of three mutually orthogonal directions. The second magnet 104 is disposed relative to the second pair of Hall Effect sensors 106 such that that they are operative together to sense relative displacement in each of three mutually orthogonal directions. The third magnet 108 is disposed relative to the third pair of Hall Effect sensors 110 such that that they are operative together to sense relative displacement in each of three mutually orthogonal directions. In each pair of Hall Effect sensors, one sensor faces upwards and the other sensor faces towards one side such that they are oriented at ninety degrees to each other. As a result one of the sensors in a pair senses displacement in the x and y directions only and the other sensor in the pair senses displacement in the x and z directions only. Outputs from both sensors in a pair are therefore used to sense displacement in the x, y and z directions. The Hall Effect sensor pairs 102, 106, 110 are mounted on the base portion 58 of the apparatus of Figure 3 such that they do not move upon deformation of the resiliently deformable body 56. The Hall Effect sensor pairs 102, 106, 110 are mounted such that adjacent sensor pairs are at 120 degrees when viewed from above as shown in Figure 10. The first to third magnets 100, 104, 108 are supported in the resiliently deformable body 56 such that they are above and around the Hall Effect sensor pairs 102, 106, 110 with each magnet being generally aligned with its respective Hall Effect sensor pair. The first to third magnets 100, 104, 108 are therefore capable of moving independently of each other in dependence on deformation of the resiliently deformable body 56.

The processing apparatus described above is operative to receive an output from each Hall Effect sensor pair 102, 106, 110 and to make displacement determinations in dependence on the received outputs. More specifically, the processing apparatus determines the displacement of each magnet in relation to its Hall Effect sensor pair in the x, y and z directions. In addition the processing apparatus is operative to determine the displacement of the magnets relative to each other and the orientation of each of the magnets. The processing apparatus is therefore capable of sensing more complex deformations than can be achieved with the arrangement of Figure 3.

More specifically and considering the arrangement of Figure 10 further the processing apparatus can sense deformation involving compression of opposing sides and also compression from opposing sides that is asymmetric. Also the processing apparatus can sense deformation which involves a change in orientation of the magnets such as a twisting action in which the top of the resiliently deformable body 56 is rotated relative to the bottom of the resiliently deformable body 56 about an axis which extends upwards from the base portion 58. In an alternative embodiment, the three magnets 100, 104, 108 are mounted on a rigid annulus which is supported by the resiliently deformable body 56. The three magnets 100, 104, 108 are therefore incapable of relative movement whereby the processing apparatus is capable of sensing a more limited but yet still relatively wide range of deformations. More specifically, the processing apparatus is capable of sensing deformations involving a change in orientation of the magnets but not deformations which are non-uniform between the magnets.

Claims

Claims 1. Apparatus for generating sound comprising: a resiliently deformable body; and a sensor arrangement, the sensor arrangement comprising first and second sensor parts which are disposed such that the resiliently deformable body is operative upon deformation to displace at least one of the first and second sensor parts relative to the other and is operative upon return from deformation to return the first and second sensor parts to substantially a same relative disposition that the first and second sensor parts had before deformation, the sensor arrangement being operative to generate a sensor output signal in dependence on displacement of at least one of the first and second sensor pads relative to the other, the sensor output signal corresponding to at least one sound.
2. Apparatus according to claim 1 wherein the resiliently deformable body defines an exterior surface of sufficient surface area to permit direct manipulation by a user.
3. Apparatus according to claim 1 or 2 wherein each of the first and second sensor parts is one of disposed on and disposed within the resiliently deformable body.
4. Apparatus according to any one of the preceding claims wherein the apparatus is configured such that upon deformation an extent of change of relative disposition of the first and second sensor parts is less than an extent of movement of an exterior surface of the resiliently deformable body caused by manipulation by a user.
5. Apparatus according to claim 4 wherein at least one of the first and second sensor parts is disposed within the resiliently deformable body at a location spaced apart from the exterior surface.
6. Apparatus according to claim 4 or 5 configured such that a force applied at the exterior surface is mechanically coupled to at least one of the first and second sensor parts by way of solely one path, the path comprising the resiliently deformable body.
7. Apparatus according to any one of the preceding claims configured such that displacement of the first and second sensor parts relative each other comprises movement of at least one of the first and second parts relative to the other in each of at least three mutually perpendicular directions.
8. Apparatus according to claim 7 wherein movement in each of at least three perpendicular directions comprises linear translation of at least one the first and second sensor pads.
9. Apparatus according to claim 7 or 8 configured to provide for determination of deformation involving rotation about at least one axis.
10. Apparatus according to any one of the preceding claims wherein the first and second sensor pads are operative of themselves to sense movement in each of at least three mutually perpendicular directions.
11. Apparatus according to any one of the preceding claims wherein the sensor arrangement is operative to generate the sensor output signal on an electromagnetic basis.
12. Apparatus according to claim 11 wherein the sensor arrangement is configured to provide an electrical output which changes in dependence on a strength of a sensed magnetic flux density.
13. Apparatus according to claim 11 or 12 wherein the sensor arrangement comprises a Hall Effect sensor arrangement in which the first sensor part comprises a permanent magnet and the second sensor part comprises a Hall Effect sensor.
14. Apparatus according to any one of the preceding claims wherein the sensor apparatus comprises a third sensor part which is disposed at a spaced apart location from the second sensor part, the apparatus for generating sound being configured to sense displacement of the first and second sensor parts relative each other and displacement of the first and third sensor parts relative each other.
15. Apparatus according to any one of the preceding claims further comprising a sound generating arrangement which is operative to generate sound in dependence on the sensor output signal.
16. Apparatus according to claim 15 wherein the sound generating arrangement is comprised in a unitary arrangement which also comprises the resiliently deformable body.
17. Apparatus according to claim 15 wherein the sound generating arrangement is not comprised in a unitary arrangement comprising the resiliently deformable body.
18. Apparatus according to any one of the preceding claims further comprising processing apparatus which is operative to determine displacement of the first and second sensor pads.
19. Apparatus according to claim 18 wherein the processing apparatus is configured to determine a direction of displacement of the first and second sensor parts in relation to each other in dependence on an output signal from the sensor arrangement.
20. Apparatus according to claim 18 or 19 wherein the processing apparatus is configured to determine an extent of displacement of the first and second sensor parts in relation to each other.
21. Apparatus according to any one of the preceding claims configured to sense displacement of the first and second sensor parts relative each other in three mutually perpendicular directions and to provide respective three quantities in dependence thereon, wherein the apparatus is operative to determine two different ratios of pairs of the three quantities and make a determination in respect of deformation of the resiliently deformable body in dependence on the two different ratios.
22. Apparatus according to any one of the preceding claims configured to perform pattern recognition on quantities based on sensor output signals generated by the sensor arrangement to thereby determine a particular form of deformation of the resiliently deformable body.
23. Apparatus according to any one of the preceding claims wherein the resiliently deformable body comprises gaseous voids.
24. Apparatus according to any one of the preceding claims wherein the resiliently deformable body comprises a polymer.
25. Apparatus according to any one of the preceding claims wherein the resiliently deformable body is configured to be deformable along three mutually orthogonal directions.
26. Apparatus according to any one of the preceding claims wherein the resiliently deformable body is generally cuboid in form.
27. Apparatus according to any one of the preceding claims further comprising a filter which is configured to reduce a response arising from a slow return of the resiliently deformable body from deformation.
28. Sound generating apparatus comprising apparatus for generating sound according to any one of the preceding claims and audio apparatus which is operative to emit sound in dependence on a signal received from the apparatus for generating sound.
29. Sound generating apparatus comprising plural apparatus for generating sound which are each configured and operative according to any one of claims 1 to 27, processing apparatus comprised in the sound generating apparatus being configured to be operative in dependence on signals from the plural apparatus for generating sound.