EP3758858A1

EP3758858A1 - Vibroacoustic device

Info

Publication number: EP3758858A1
Application number: EP19713091.7A
Authority: EP
Inventors: Alban Duroy
Original assignee: Studio Duroy
Current assignee: Studio Duroy
Priority date: 2018-02-28
Filing date: 2019-02-26
Publication date: 2021-01-06
Also published as: FR3078432B1; FR3078432A1; WO2019166705A1

Abstract

The invention relates to a powerful, but compact, vibroacoustic device which is capable of transmitting a large portion of the musical sound spectrum without emitting a loud output volume so as not to disturb individuals nearby. The invention relates to a vibroacoustic device comprising a permanent magnet (101) generating a permanent magnetic field in a space (102) known as an air gap, and a coil (103) of electrically conductive wire arranged in said air gap in the axial direction (X-X) and provided with two electrical terminals, the coil (103) being rigidly connected to a plate (104) onto which a rod (105) is attached which is capped by a disk (106) covered with a layer of elastomer (107-108) and intended to rest on the chest of a user during use.

Description

VIBROACOUSTIC DEVICE.

The invention relates to a vibroacoustic device.

A piece of music consists of sounds of different frequencies. The volume of the sound impacts these frequencies differently: thus, at equal volume, high frequencies are less than low frequencies. This is because the bass is felt more strongly by the whole body than the highs.

Therefore, when a person increases the volume of the sound to better distinguish the highs, it inflicts on his body, and especially his ears, vibrations that can be harmful in the short, medium or long term.

Moreover, some legislations limit the level of bass allowed in audio devices, especially for headphones, to limit the risk of deafness.

The balance between bass and treble is also part of the criteria to note the quality of an audio device.

The problem posed by the sound volume of audio devices, and in particular headphones, is all the more important as more and more people listen to music from their smartphone.

To limit the risk of deafness, it has already been proposed devices that automatically limit the sound volume beyond a certain period of use. Nevertheless, these systems can always be forced by the user, because this is only a proposal made by the device.

A completely different type of device offers external noise reducers, so that the user is not bothered by these noises and does not increase the sound too much. However, these noise limiters all operate on the same principle of capturing the external noise and emitting in the headphones an identical sound, but inverted frequency, so that the noise is canceled.

If the outside noise is no longer captured by the ear, the latter nevertheless undergoes a sound pressure twice as strong without the user realizing it. This results in very frequent headaches.

To limit the impact of bass on the ears, it has already been proposed audio systems physically separating the bass speakers of medium and high frequency speakers.

In particular, to limit noise, it has already been proposed to remove the membrane of the bass speakers so that they transmit only vibrations, not sound, to the body.

However, these devices have never been entirely satisfactory because of the low level of sensation felt and often the inconvenience of having a long time against a vibrating housing.

There may be mentioned, for example, the device "WOOJER®" which comprises a vibratory mechanism enclosed in a housing carried either by a strap or a jacket.

The box is connected to an audio device (digital walkman type) and headphones, and vibrates according to the rhythm of the music (so only depending on the bass). It only vibrates on low frequencies below 500Hz.

This device has many disadvantages. Most importantly, the casing in which the vibration mechanism is located transmits little vibration. It is then necessary either to increase the power strongly to feel the vibrations or to strongly press the device against the body. However, the strap system proposed by the WOOJER system does not allow such a tightening: even tightening tightly the strap, the tightening is done at the level of a shoulder and an armpit, but little at the level of the thorax. It follows that in use, so that all is comfortable to wear, do not over tighten the strap to breathe. In doing so, the housing is not supported against the thorax which, combined with its structure, does not allow to transmit vibrations effectively.

There may also be mentioned the device "SUBPAC®" which comprises a vibratory mechanism enclosed in a case carried by a backpack. This device, addressed to musicians, is much more powerful than the WOOJER device, because the housing is much larger and contains several vibratory mechanisms distributed over a wide area corresponding to the back of the user.

This device is, therefore, heavy and bulky. In addition, as for the previous device, it requires a powerful tightening of the straps of the bag to promote contact between the shell of the housing and the body of the user.

However, the vibrations transmitted to the back of the user do not allow to effectively feel the low frequencies.

But the box vibrates only according to the rhythm of the music (so only depending on the bass). It vibrates only at low frequencies between 1 Hz and 200 Hz, the goal being to allow a musician to produce or mix music longer without damaging his ears, feeling the low frequencies rather than listening to them. .

An object of the present invention is therefore to provide a powerful vibrating device, but not bulky, capable of transmitting a large part of the sound spectrum of the music (thus perceptible by humans, that is to say between 20 Hz and 20 Hz. about kHz) and not only the bass, without emitting a loud volume to the outside so as not to disturb the people around. Another object of the invention is to provide a vibrating device that effectively transmits vibrations without requiring too much tightness against the body of the user.

The idea of the invention is to put the vibrating part of the vibratory mechanism directly in contact with the chest of the user (and not enclosed in a casing), the vibrating part transforming the thorax of the user into a membrane emitting the sound towards the inside of the body, in particular by using the rib cage as a sounding board.

According to the invention, the transduction of sound by the body of the user is done through a rigid vibrating disc covered with a layer of elastomer, preferably silicone, which ensures transmission of the entire sound spectrum of the music ( the spectrum being advantageously filtered) and not simply the low frequencies.

To this end, the subject of the invention is a vibroacoustic device comprising a permanent magnet generating a permanent magnetic field in a gap called air gap, and a coil of electrically conductive wire arranged in this gap in the axial direction and provided with two terminals. in which the coil is secured to a plate on which is fixed a rod surmounted by a disk covered with an elastomer layer intended, in use, to bear against the thorax of a user.

According to other embodiments, which can be combined with one another:

The vibroacoustic device can be housed in a housing carried by one end of a resilient hoop shaped so that, in use, the elastomer layer bears against the thorax of a user and a second end of the hoop resting against the back of the user;

The second end of the arch may be provided with a battery electrically connected to the housing of the first end; The vibroacoustic device may comprise a microcontroller connected to a receiver of an audio signal intended to be transmitted, in use, from an audio source, the microcontroller being connected to the electrical terminals of the coil and programmed to electrically power the electrical terminals according to an audio signal received from the audio source, in use;

• the receiver can be wired and include a wired connection socket to an audio source;

The receiver may be wireless and include a wireless audio signal receiving antenna and a transducer transforming the wireless audio signal into an electrical signal;

• the microcontroller can be programmed to filter certain frequencies of the audio signal before powering the electrical terminals;

• the filtration may include attenuation of certain frequencies of the audio signal;

• the microcontroller can be programmed to attenuate at least the 60 Hz, 91 0 Hz, 3.6 kHz and 1 4 kHz frequencies;

The housing may comprise adjustment buttons connected to the microcontroller to choose one or more frequencies to be filtered;

• The housing may include adjustment buttons connected to the microcontroller to set a filter to be applied on one or more frequencies;

The elastomer layer may have a curved profile;

The elastomer layer may have a spherical cap shape;

The elastomer layer may have a convex spherical cap shape;

The elastomer layer may have a concave spherical cap shape; The elastomer layer may have a maximum thickness of 2 mm and the rod has a length of between 0.5 cm and 1.5 cm, preferably 1 cm; and or

The elastomer may be chosen from silicones and rubber.

Other features of the invention will be set forth in the detailed description below, made with reference to the accompanying drawings, which represent, respectively:

Figure 1 is a schematic sectional view of a first embodiment of a vibroacoustic device according to the invention;

Figure 2 is a schematic sectional view of a vibroacoustic device according to the invention mounted at one end of a bow provided with a housing; Figure 3 is a schematic sectional view of a second embodiment of a vibroacoustic device according to the invention;

- Figures 4 and 5, schematic views of an example of mounting a vibroacoustic device according to the invention on a user, respectively front and back;

Figure 6 is a schematic side view of an exemplary mounting of a vibroacoustic device according to the invention on a user; and

- Figure 7, a schematic front view of a variant of the vibroacoustic device according to the invention mounted on a strap carried by a user.

FIG. 1 illustrates a vibroacoustic device 1 00 according to the invention. It operates on the same principle as conventional loudspeakers: it comprises a permanent magnet January 01 generating a permanent magnetic field in a given space called air gap 102, and a coil 1 03 of conductive wire of electricity arranged in this gap in the axial direction XX and provided with two electrical terminals (not shown in the figure).

When an electric current flows through this coil, the latter tends to leave the permanent magnetic field of the gap in the axial direction. Thus, by varying the voltage as a function of the musical signal, the coil tends to enter and leave the gap 1 02.

Thus, the vibroacoustic device according to the invention is an electromechanical transducer which transforms an electrical signal (the audio signal) into a mechanical movement.

However, unlike conventional loudspeakers, the vibroacoustic device 1 00 according to the invention has no membrane, so that it does not generate sound by itself.

According to the invention, the coil 1 03 is secured to a plate 1 04 on which is fixed a rod 1 05 surmounted by a disc 1 06 covered with a layer of elastomer 1 07, rubber or preferably in silicone, intended to be in support against the chest of a user.

Advantageously, the elastomer layer 107 is not flat but has a curved profile, preferably in the form of a spherical cap. In Figure 1, the elastomer layer 1 07 has a convex spherical cap shape, while in Figure 3, the elastomer layer 1 08 has a concave spherical cap shape.

The curved shape of the elastomer layer provides optimal vibration transmission to the user's body without requiring too much application force.

In a preferred embodiment, the elastomer layer 1 07-1 08 has a maximum thickness of 2 mm and the rod 105 has a length of between 0.5 cm and 1.5 cm, preferably 1 cm. The rod 105 of approximately 1 cm provides a space E between the plate 104 and the disk 106 which allows the vibrations to be transmitted with optimum power to the body of the user. With a shorter stem, it is necessary to amplify the signal strength to obtain the

5 same result.

As illustrated in FIG. 2, the vibroacoustic device 1 00 according to the invention is advantageously housed in a housing 1 1 0 carried by an end 1 21 of an elastic arch 1 20. Unlike the elastic hoops of the conventional audio headphones, the hoop according to the invention is shaped so that,

Ί 0 in use, the elastomer layer bears against the thorax of a user and a second end of the arch bears against the back of the user (see Figures 4 to 6).

The housing 1 1 0 receiving the vibroacoustic device 1 00 according to the invention has a housing 1 1 1 for the device, and a lid

1 5 1 1 2 provided with a hole 1 1 3 for the passage of the rod 1 05 of the device 1 00.

Thus, according to the invention, the rod 1 05 passes through the cover 1 1 2 of the housing and the elastomer layer 1 07 (or 1 08) bears against the chest of a user during use.

The housing 1 1 0 also comprises a microcontroller 1 14

20 connected to a receiver 1 1 5 of an audio signal transmitted from an audio source, via a signal amplifier 1 1 6.

The microcontroller 1 14 is connected to the electrical terminals of the coil and programmed to electrically power, in use the electrical terminals of the coil according to an audio signal received from the source

25 audio (and amplified by the amplifier).

In the illustrated embodiment, the receiver 1 1 5 is a so-called "auxiliary" connection jack type "Jack", 3.5 mm in diameter to connect an audio source such as a digital music player. In In this case, the receiver 1 15 is connected by wire connection to the microcontroller 1 14 (these connections are not illustrated for the sake of clarity of the figures).

Alternatively, or in combination, the device according to the invention comprises a wireless receiver, for example of the Bluetooth® or WiFi type. It then comprises a wireless audio signal receiving antenna and a transducer transforming the wireless audio signal into an electrical signal to the microcontroller 1 14.

The audio signal is preferably amplified to generate an amplified electrical signal transmitted to the coil. To this end, the housing includes 1 1 7 volume up and down control buttons controlling the adjustable signal amplifier 1 1 6.

According to an advantageous embodiment, the hoop 1 20 (or alternatively the housing 1 1 0) comprises a connection socket 1 23 for an audio headset, to allow the user to combine the sensation transmitted by the vibroacoustic device according to the invention with the normal hearing of music with headphones.

To supply all the electronic components, the vibroacoustic device according to the invention is connected to a battery.

Advantageously, the second end 1 22 of the arch 1 20 comprises a housing 1 30 provided with a battery electrically connected to the housing 1 10 of the first end 1 21 (see Figures 5 and 6).

Thanks to the contact between the elastomer layer 1 07-1 08 with the thorax (in particular the region of the solar plexus) of the user, the vibrations are transmitted very efficiently.

The curved elastomer layer 1 07-1 08 combined with the rod

1 05 allows the transmission to the user of the entire musical spectrum, not just bass. The user's ribcage interior is transformed into a sound box and the ribcage itself acts as the membrane of the conventional loudspeakers.

The sounds are really felt by the user thanks to

5 vibrations, and heard by the user through the sounds emitted inside his body and transmitted to his inner ear by his own body.

Thus, the device according to the invention vibrates and generates an acoustic wave in the body of the user.

The use of an elastic arch ensures a perfect contact between

Ί 0 the elastomer layer and the body, without impeding the breathing of the user.

Unexpectedly with regard to the state of the art, the device according to the invention having dimensions of the order of a few centimeters transmits the vibrations very effectively.

The experience can even be a little tiring because all

1 5 vibrations are transmitted. The inventor realized that by filtering certain frequencies, the use became much more pleasant and could be supported for several hours.

Thus, in a preferred embodiment, the microcontroller 1 14 is programmed to filter certain frequencies of the audio signal before

20 to electrically power the electrical terminals of the coil 103.

Preferably, this filtration comprises attenuation of certain frequencies of the audio signal, in particular the frequency bands centered on 60 Hz, 910 Hz, 3.6 kHz and 14 kHz. Advantageously, the frequency band centered on 230 Hz is also attenuated. The width of the band

Filtered depends on the quality of the components used. Overall, a band of 5 Hz to 10 Hz wide is preferred. Typically, the frequency bands centered on 60 Hz, 91 0 Hz, 3.6 kHz and 14 kHz are attenuated by 1 5 decibels, and the frequency band centered on 230 Hz is attenuated by 5 decibels.

The choice of bands and their attenuation generally depend on the size of the vibroacoustic device and the user.

In an advantageous embodiment, rather intended for professionals, the housing 1 1 0 (or the hoop 1 20) comprises adjustment buttons connected to the microcontroller to choose one or more frequencies to filter, and to adjust a filter to apply on the frequency (s) (typically the attenuation value).

The effectiveness of the vibroacoustic device according to the invention is such that it is possible to use it with a strap 200 (see FIG. 7) and not with an elastic arch 1 1 0, while obtaining an efficient transmission of vibrations in the whole spectrum of music (possibly partially filtered).

In this embodiment, the vibroacoustic device is housed in a housing 300 attached to the strap, the housing comprising a lid provided with an orifice 3 1 3 to let the rod 1 05 and allow contact between the elastomer layer and the user (see Figure 3).

With the vibroacoustic device according to the invention, the tightening of the strap does not need to be too strong and does not risk to hinder the breathing of the user.

The user receiving part of the music thanks to the vibroacoustic device according to the invention, he can lower the sound of his headphones and preserve his hearing.

In addition, the volume emitted outwardly by the vibroacoustic device according to the invention is very limited and allows not to disturb the people around while feeling very strongly the music itself.

Claims

1. Vibroacoustic device comprising a permanent magnet (1 01) generating a permanent magnetic field in a gap (1 02) called air gap, and a coil (1 03) of electrically conductive wire arranged in this gap in the axial direction (XX) and provided with two electrical terminals, characterized in that the coil (103) is integral with a plate (1 04) on which is fixed a rod (1 05) surmounted by a disc (1 06) covered with a layer of elastomer (1 07-1 08) intended, in use, to bear against the thorax of a user.

2. vibroacoustic device according to claim 1, wherein the vibroacoustic device (1 00) is housed in a housing (1 1 0) carried by one end (1 21) of an elastic arch (1 20) shaped so that, in use, the elastomer layer (1 07-1 08) bears against the thorax of a user and a second end (1 22) of the arch bears against the back of the user.

3. vibroacoustic device according to claim 2, wherein the second end of the bow is provided with a battery electrically connected to the housing of the first end.

4. Vibroacoustic device according to any one of claims 1 to 3, comprising a microcontroller (1 14) connected to a receiver (1 1 5) of an audio signal intended to be transmitted, in use, from an audio source, the microcontroller being connected to the electrical terminals of the coil (1 03) and programmed to electrically power the electrical terminals according to an audio signal received from the audio source, in use.

The vibroacoustic device according to claim 4, wherein the receiver is wired and includes a wired connection socket (11) to an audio source.

The vibroacoustic device according to claim 4, wherein the receiver is wireless and comprises a wireless audio signal receiving antenna and a transducer transforming the wireless audio signal into an electrical signal.

7. Vibroacoustic device according to any one of claims 4 to 6, wherein the microcontroller is programmed to filter certain frequencies of the audio signal before powering the electrical terminals.

Vibroacoustic device according to claim 7, in which

Which filtration comprises attenuation of certain frequencies of the audio signal.

9. A vibroacoustic device according to any one of claims 7 to 8, wherein the microcontroller is programmed to attenuate at least the 60 Hz, 91 0 Hz, 3.6 kHz and 14 kHz.

A vibroacoustic device according to any one of claims 7 to 9, wherein the housing (1 1 0-200) comprises setting buttons connected to the microcontroller to select one or more frequencies to be filtered.

1 1. Vibroacoustic device according to any one of claims 7 to 10, wherein the housing (1 1 0-200) comprises buttons

20 of adjustment connected to the microcontroller to set a filter to be applied on one or more frequencies.

2. A vibroacoustic device according to any one of claims 1 to 1 1, wherein the elastomer layer (1 07-1 08) has a curved profile.

3. The vibroacoustic device according to claim 12, wherein the elastomeric layer (107-100) has a spherical cap shape.

14. Vibroacoustic device according to claim 1 3, wherein the elastomer layer (1 07) has a convex spherical cap shape.

Vibroacoustic device according to claim 1 3, wherein the elastomer layer (1 08) has a concave spherical cap shape.

6. vibroacoustic device according to any one of claims 1 to 1 5, wherein the elastomer layer (1 07-1 08) has a maximum thickness of 2 mm and the rod has a length of between 0.5 cm and 1.5 cm, preferably 1 cm.

7. Vibroacoustic device according to any one of claims 1 to 1 6, wherein the elastomer is selected from silicones and rubber.