WO2008133490A2

WO2008133490A2 - A sound processing device

Info

Publication number: WO2008133490A2
Application number: PCT/MY2008/000036
Authority: WO
Inventors: Jin Hem Thong
Original assignee: Jin Hem Thong
Priority date: 2007-04-30
Filing date: 2008-04-30
Publication date: 2008-11-06
Also published as: WO2008133490A3

Abstract

A sound processing device (100) having means to generate a responding sound signal (25) for termination, alteration or volume reduction of the voice signal (38) is disclosed. The device (100) comprises a means for receiving sound signal (15). a means for processing the received sound signal and generating a responding signal (25). and a means for emitting the responding signal (5). The device (100) generally receives the voice signal (38) produced as a person speaks, processes the sound signal (38) and emits a responding signal (48) for cancellation, alteration or volume reduction of the sound signal (38). The device (100) aims to preserve privacy in conversation, which lacks thereof nowadays, concerning the usage of cellular phones (60) and other communication devices and prevention of eavesdropping or overhearing can be achieved. The said device (100) also aims to provide an user-enabled proactive measure to courteously prevent our conversation or speech from disturbing others around or in the vicinity.

Description

A SOUND PROCESSING DEVICE

FIELD OF THE INVENTION

The present invention relates to a sound processing device and more particularly to an apparatus comprising means to instinctively generates anti-phase sound signal for elimination of a voice signal, generates responding sound signal that alter the voice signal and also generates responding sound signal for volume reduction of the voice signal. The device is intended to preserve privacy which lacks thereof nowadays. concerning of not only the prevalent usage of cellphones, fixed-line phones and other communication devices but also daily conversations which usually occur in conferences or interviews.

BACKGROUND ART

Conversation is required to convey a message. With the advent of the telecommunication device, conversation is further enhanced to not only restricted to face-to-face. Communication through long distance enabled by the telecommunication device has since been a reality which is welcomed by everyone. Although the usage of telecommunication device has improved our life tremendously but unfortunately we are still not spared from certain shortcomings.

Engaging conversation at public places is deemed not a pleasurable experience as it tends to invite undesirable stares and attentions due to the commotion caused by having conversation. Besides normal face-to-face conversation, this disadvantage also stretches to the usage of cellular phones. As a result, measures have been taken in library and cinema in which a rule is imposed to prohibit the usage of cellular phones that unforgivably disrupt other people's attention.

In addition to that, having conversation always does not stall other people from overhearing our conversation._. Disadvantages have to be endured by the speakers for permitting people which are not involved in the conversation to overhear. Outsiders can eavesdrop easily or accidentally listen to what is being spoken. In this case, we are left helpless in safeguarding our privacy.

Sound is often interpreted as a physical sensation that ears sensitively respond to. More specifically, it is actually very much defined as a form of longitudinal waves produced by said vibrating object that our hearing sense decipher as sound. Sound has to be produced by a source and normally the source is the vibrating object. The vibration of said object causes energy being transmitted through the air and said longitudinal waves are the transferring means of the energy. Later, the sound in the form of longitudinal sound waves are collected by an ear or an instrument to have the sound being heard.

Voice is generally referred to sound naturally generated by one's speaking. Voice is also produced by a source which vibrates at certain frequencies and the meant source that capable of performing said vibration is the vocal cords. The vocal cords are technically made of folds of flesh. These folds of flesh vibrate at a certain frequency largely determined by the muscles that control them. The vibration would subsequently releases sound waves which later would be deciphered by the listener through the ears. As mentioned, these sound waves are spread outwardly to allow the energy being transferred. The sound waves can not be preferably directed solely to a certain intended listeners. Unintended listeners would undoubtedly hear the content of the conversation or find the commotion discomforting.

As a matter of fact, these shortcomings of havmg a private conversation which does not disturb others at the same time must be remedied in order to preserve privacy and peace.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a device and a method using such a device for voice signal cancellation, alteration or volume reduction.

In accordance with the present invention, it is comprised of a means for receiving sound signal, a means for processing the waveform of the received sound signal and generating a responding signal and a means for emitting the responding signal.

It is an object of the invention to provide a voice cancellation device that is intended to preserve the privacy in conversation which is lack thereof nowadays and also to hinder from causing commotion and disturbance to others while conversing. A voice signal would be received and processed to generate another responding signal. The generated responding signal would be subsequently emitted and combines with the voice signal consequently cancelling the voice signal.

The voice signal and the responding signal are characterized to have a substantially the same frequency and substantially the same amplitude, the cancelling signal has a same waveform as the sound signal but both signals are out of phase with a phase difference of substantially 180 degrees.

It is another object of the present invention to provide a sound processing device that alter the waveform of the voice signal. Said processing device receives a voice signal. processes it and generates a responding signal. The responding signal would be emitted and combines with the voice signal to have the waveform of the voice signal totally altered. The requirements that need to be applied are the voice signal and the responding signal composes substantially the same frequency and substantially the same waveform but both signals are substantially out of phase with a corresponding phase difference.

It is another object of the present invention to provide a sound processing device that reduce the volume of the voice signal. The voice signal would be received and a responding signal would be generated. The responding signal composes substantially the same frequency and substantially the same waveform, the amplitude of the responding signal consisted substantially in the range that is reduced from the voice signal amplitude, and both signals are out of phase with a phase difference of substantially 180 degrees.

The responding signal and the sound signal propagate in a chosen same region of space: and the responding signal propagates at time that in cohesion with the sound signal.

According to the practice of the invention there is also provided a method of cancelling, altering or reducing the volume of a sound signal comprising receiving a sound signal. analyzing the sound signal, generating a responding signal which has characteristics that substantially eliminate, alter or reduce volume of the sound signal by emitting the responding signal.

The present invention consists of certain novel features and a combination of parts hereinafter fully described and illustrated in the accompanying drawings and particularly pointed in the appended claims: it being understood that various changes in the details may be without departing from the scope of the invention or sacrificing any of the advantages of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawings the preferred embodiments from an inspection of which when considered in connection with the following description, the invention, its construction and operation and many of its advantages would be readily understood and appreciated.

FIG. 1 shows a flow chart describing the process performed by the present invention FIG. 2 shows the combination of a voice signal wave and a responding signal wave resulting the voice signal wave being cancelled.

FIG. 3 shows the combination of a voice signal wave and a responding signal wave producing a resultant wave with a reduced amplitude.

FIG. 4 shows the combination of a voice signal wave and a responding signal wave resulting the voice signal being altered.

FIG. 5 shows the possible arrangement of the present invention.

FIG. 6 shows one of the embodiment of the present invention in operation.

FIG. 7 shows one of the embodiment of the present invention which is the portable sound processing device. FIG. 8 shows one of the embodiment of the present invention in operation.

FIG. 9 shows the present invention being embedded in a handsfree kit.

FIG. 10 shows the usage of the present invention being embedded in home or office appliances, fixtures and furniture.

FIG. 11 shows the present invention being used in a fixed line by telephone operator or in a customer service center.

FIG. 12 shows the present invention being used or incorporated in the computer or laptop. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to a voice cancellation device. More particularly, the present invention relates to an apparatus having a means to instinctively generates anti- phase sound waves for elimination of voice. Hereinafter, the voice cancellation device shall be described according to the preferred embodiments of the present invention and by referring to the accompanying description and drawings. However, it is to be understood that limiting the description to the preferred embodiments of the invention and to the drawings is merely to facilitate discussion of the present invention and it is envisioned that those skilled in the art may devise various modifications without departing from the scope of the appended claim.

Two waves when travels simultaneously through the same area of space would inherently interfere. Sound which is in respect one type of wave also does not exclude itself from the interference phenomenon.

If we study a sound waveform, it is apparent that the wave consists of crests and troughs. The crests are represented by the compression in the air whereas the troughs are the result of the rarefaction. A trough is located between two crests. If for instance two waves with the same frequency and the same amplitude are being emitted simultaneous!} from two distinct sources, constructive and destructive interferences can occur depending on the phase orientation of both waves.

If two waves happen to be in same phase and meet up at some location, both waves would simultaneously have crests and troughs at the same time. Listener in the vicinity where the two waves interfere would experience a loud sound because the waves are said interfered constructively. Therefore by having the same phase, the resultant wave courtesy of this wave combination would have a larger amplitude on its crests and troughs compared to the original waves.

On the contrary, the opposite outcome would occur if said two waves have different phase orientation. To totally eliminate both waves, a destructive interference needs to take place. One wave must have crests and troughs positioned at complete opposition of the other wave's. When both waves are in collision, crests of one wave meet the trough of the other. The compressions of the air being represented by the crests are canceled out by the rarefactions of the wave or vice versa. Destructive interference is experienced with the listener in the vicinity does hear nothing at all. Both waves are said to be out of phase by one-half wavelength based on the occurrence of the destructive interference. As illustrated in Figure 2, the produced resultant wave (52) is a straight line as all of the crests and troughs are eliminated due to the strategic phase positioning of the waves.

Destructive interference can only occur provided the two waves (32 & 42) of which the crests of one wave is misplaced from the crests of the other wave by exactly one-half wavelength. In this case, the displacement of the waveforms is usually measured by phase difference. Phase difference is expressed in degrees which primarily ranges from 0 to 360 degrees. To have two waves which have the same frequency and amplitude cancel out each other, the difference of both waves^" phases has to be precisely 180 degrees. In this instance, the two signals (32 & 42) are deemed to be anti-phase towards each other. The combination of these two signal waves (32 & 42) ultimately form a straight line wave (52) causing no sound would be detected. Said criterion for sound signal elimination is taken into account to conceive a sound processing device (100) as will be hereinafter described in greater detail.

The present invention relates to a sound processing device (100). The sound processing device (100) is comprised of several parts. The first part being the means for receiving voice signal (15). The second being the means for analyzing the waveform of the received voice signal (25) and generating a responding signal (48). The third being the means for broadcasting the generated responding signal (5).

Referring now to Figure 5, a plurality of microphones (15a) may be employed as the means for receiving voice signal (15). Voice signal (38) is produced when a person is speaking. The voice signal (38) would travel in an outward direction from the source enabling people around the speaking person to hear what is being spoken. To prevent the voice signal (38) being spread around, the voice signal (38) produced is recorded by said microphone (15a) of the sound processing device . The microphone (15a) for sensing the voice signal (38) subsequently converts the voice signal (38) into an electrical signal. Then, the electrical signal is studied scrupulously by the analyzing means (25) and consequently determining the undulating waveform of the voice signal (38). The analyzing means (25) can be a microprocessor or any type of processors created specifically for the purpose depending on the preferred embodiment. In this case, a computerized system operates in. as the analyzing means, dissecting the voice signal in a systematic extent which would determine another sound signal called responding signal (48) with characteristics required to suit certain criterion as will be elaborated in greater detail hereinafter. The electrical signal containing the information of the responding signal (48) would then be converted in concert to a sound by speakers (5a) which function as the means for emitting the responding signal (5).

It is therefore one aspect of the present invention to provide a sound processing device (100) strategically disposed in the proximity where at least one user is participating in a conversation is the kind set forth for effectively cancel the voice signal (38) produced by the user intending to further prevent the conversation from being heard by anyone.

The sound processing device (100) may be automatically activated when a user activates the device (100) or the user could have said device (100) manually activated as and when needed. The voice signal (38) emitted from the user would then be interposed by preferably a plurality of microphones (15a) disposed adjacent to the source of the voice signal. The sound data collected by the microphone (15a) is later transmitted to a processing unit (25) such as a computerized system embedded in said sound processing device ,(100). The system (25) deciphering the data yields the waveform of the voice signal (38) so as to generate, with reference to the waveform of the original voice signal

(38), a responding sound signal (48) which would be later being broadcast by a plurality of speakers (5a). The responding signal (48) propagates out from the speakers (5a) and collides with the sound signal (38) resulting total cancellation of the voice signal (38). The cancellation of voice signal is effective provided that the voice signal (38) and the responding signal (48) travel in the same region of space and at a time in cohesion with the voice signal propagation. The spreading responding signal (48) emitted bears closely the duplicate resemblance to the voice signal (38) but they are 180 degrees out of phase from each other. The responding signal (48) is characterized with the same amplitude and the same frequency as the voice signal (38). In order to have a destructive combination of both signals (38 &

48). the phase difference between the two signals must be set precisely at 180 degrees.

Said two signals (38 & 48) which are anti phase to each other, at the time of collision. would be destructed entirely. Both signals (38 & 48) must also travel in the same region of space enabling them to be combined for elimination.

The criterion must be met in order to have the total elimination of two sound waves which is said two waves must comprise the same frequency and the same amplitude and are projected out of phase by 180 degrees. However, a targeted primary sound signal (36) can be partially canceled by having a secondary sound signal (46) in response to the primary sound signal (36) consisting of a similar frequency but a different amplitude, as shown in Figure 3. The amplitude of the secondary sound signal (46) as being lesser than said primary sound signal (36) can enable a reduction of the targeted primary sound signal (36).

As such, according to another aspect of the present invention, there is also provided a sound processing device (100) for reducing the audibility of a sound signal (38). As shown in Figure 5, the voice signal (38) produced by a user is also received in a similar manner like in the foregoing. After the microphone (15a) receives the voice signal (38). a processor (25) would process the electrical signal converted from the analogue format of the voice signal (38). Later, a responding signal (48) having disparate properties relatively to the cancelling signal (48) is generated. Said responding signal (56 & 48) which is generated to reduce the volume of the incoming voice signal (38) would have the relatively the same frequency as the voice signal (38) but an amplitude that is less than the sound signal amplitude. The phase difference between these two signals (36 & 46) would be half a life cycle. The responding signal (48) then would be emitted and collides with the incoming sound signal (38) as shown in Figure 5. Subsequently, the audibility which is the volume of the sound signal (38) would be decreased due to the partial elimination nature of the responding signal (48).

If the phase difference between the sound signal (38) and the responding signal waves (48) is not 180 degrees and their frequencies are equal regardless they composes the same amplitudes. The resultant wave (54) would have a waveform completely altered and different from its predecessor waves.

According to yet another aspect of the invention, there is provided a sound processing device (100) that generates responding signal (48) that alter the sound signal (38). The result would be the sound signal (34) after the collision with the responding wave (44) completely altered in terms of its waveform so that the resultant wave signal (54) which its pattern is said being disrupted would not be heard as the intended voice signal (38). User speaks and the user's voice signal (38) would be absorbed by the microphone (15a) and transmitted to the processor (25) for deciphering. The voice signal (38) after being deciphered, the processor (25) would generate another responding signal (48) which has the exact frequency of the voice signal wave (38) but having iτs phase disoriented in a portion of a life cycle, for instance. 45 degrees to consequently alter the waveform of the sound signal (38) later. After the processing and interpretation of said processors (25). the electrical signal which contains the information of the responding signal (48) would then be converted back to analogue format and released by the speakers (5a). The responding signal (48) would then collide with the voice signal (38) later effectuating a resultant wave (54) which is composed of a waveform altered from its initial voice signal form as shown in Figure 4 and 5.

As the speakers (5a) of the sound processing device (100) are unavoidable being located at the points which differ from the microphone (15a), time difference may happen due to the difference in location must be taken into consideration. The sound processing device (100) besides imposing phase shift and amplitude changes, other functions such as time shift, speed or delay is performed as well if necessary so that the responding signal (48) is adjusted accordingly tallying with the voice signal (38) for the intended purpose. The responding signal (48) must have propagation at time in cohesion with the voice signal and a corresponding phase difference from the voice signal (38) for they are vital in order to achieve a desired result.

It also may therefore said sound processing device (100) that cancels voice signal, said sound processing device (100) that reduces the audibility of a voice signal (38) and said processing device that alters the voice signal (38) may also be assembled together to produce another combined device with these three functions. Despite of that, the voice cancellation, the voice volume reduction and the voice alteration functions may also be included separately in one of its own disparate devices depending on the preferred embodiment. The present invention is at its most beneficial use when incorporated in cellular phones, PDAs, any other mobile communication devices, computer, laptop and etc. (such as during online chatting, recording or video conferencing, etc.) hands free set/kit, fixed-line phones (such as used at home, office or in call centers for operators), and appliances, furniture and fixtures (such as equipment (such as video conferencing kit etc.), wall partition, table, door, etc.). Many as speaking on cellular phones at public areas desire their conversation to be private and only heard by the other contacted person. The present invention is applied ideally of providing the solutions to said drawbacks.

In one of the preferred embodiment, it may be considered desirable incorporating the present invention into a mobile phone or any other portable communication devices like

PDA to provide the aforementioned functions in accordance with the usage of the mobile phones. Referring now to the Figure 6, it may be required to strategically place the microphone (15a) at best possible positions at the cellular phone (60). Optionally, the receiver microphone (15b) of the cellular phone may also be adapted as the means for receiving sound signal (15) for the present invention for a better efficiency. The position is deemed the most suitable as substantially all of the voice signal (38) is largely received at said microphone (15b). After the received voice signal (38) is converted into electrical signal by said microphone (15b) and processed by the computerized system (25), a responding signal (48) would be generated and then released in through speaker(s) (5b). The responding signal (48) travels towards the voice signal (38) leaving the voice signal (38) being altered or eliminated. People around the user would have adversity hearing the eliminated, altered or volume-reduced voice and the unnecessary disturbing commotion can be optimally reduced.

The voice signal (38) of the contacted person (as in the voice of the opposite party talking) emitted from the speaker of the phone (5b) which is normally audible may also be canceled, reduced its volume or altered using the present invention. As illustrated in Figure 8, the electromagnetic waves coming from the mobile phone of the person in contact that is received as digital signal to the directed user's phone (60), which later would be emitted as the contacted person voice signal, are processed by the processor (25) and a responding signal (48) is then generated. The responding signal (48) is later coherently emitted out through the sound processing device's speaker (5b) to be intersected with the outgoing contacted person's voice signal (38) for said voice cancellation, alteration or volume reduction.

In addition to that, the present invention may be attached to a hands-free kit (70) of a cellular phone. The means to receive voice signal (15) may employ the same microphone (15c) of the hands free kit (70) and the speaker (5c) (which emits the generated responding signal (48) is disposed at any optimal and strategic position). The processor (25) that processes voice signal may be attached to or detached from the handsfree kit (70) at any portion of the body thereof.

Apart from cellular phones (60) or other communication devices, the present invention may also be installed, in likewise manner as in the aforementioned cellular phones (60), on the fixed-line phone, computer or laptop or video conferencing kit so that privacy, whether in office or home, of our conversation can be preserved. With the availability of such device, users can convincingly not worry that they can no longer avoid their conversation being heard or that they might disturb others insignificantly.

In yet another alternate embodiment, a portable device including at least one of the functions aforesaid may also be provided for flexibility of a user. With reference to Figure 7, said portable device (87) can be flexibly carried around and also be kept in bag or pocket. It is understood that the portable device (87) may be operating so as to performs its functions in a similar fashion as the aforesaid embodiments, thus, it is consisted of means to receive a voice signal (15d) and a speaker (5d) that emits an antivoice signal (48).

In another alternate embodiment, the usage of the present invention is further extended to not only employed for a single user but also a group of users having a conversation. Referring to Figure 10, a group of people may usually participate in a conversation in a conference or discussion and they would be opinionated that the device (100) is useful as it assists to cancel, alter and reduce audibility of their voice when needed. This preferred embodiment is tailored to be adapted to one or more than one user for voice cancellation, voice alteration and voice audibility reduction. Microphone(s) (15e) may be optimally distributed for the intake of the participants' voice signals (38). The broadcasting speakers (15e) may be located at optimal positions, for the admission of the responding signal to be in cohesion with the voice signal of the conversation to best cancel, alter and reduce audibility of the said conversation. Signal transmission of the microphone(s) is sent to the said device to be analyzed, processed and to generate the intended responding signal to be propagated out from the speaker(s). As a result, all the voice signals (38) that travel out from the perimeter of the confined area where the said conversation is held would be generally or selectively terminated or altered by the responding signal (48). Thus, the conversation can only be heard within the confinement or within the selected area, while others will be prevented from hearing the content of the discussion.

Others can not hear or understand the conversation except those in the area where there is no responding signal (48) being transmitted. The utilization of the present invention may further be extended or embedded in appliances, furniture and fixtures or as standalone unit(s) to be used in the cars, public places, private places such as in the house or offices or in the customer service centers (for operators as shown in Figure 11), or at anywhere where one person speaks. Any other devices that emits or receives or both sound signals may also use the present invention to control and prevent the content of a conversation from being attainably heard or understand by any other people.

While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.

Claims

CLALMS

1. A sound processing device (100) for comprising:

means for receiving sound signal (15); means for processing the waveform of said received sound signal and generating a responding signal (25); and means for emitting the generated responding signal (5):

characterized in that

the sound signal (32) and the responding signal (42) characteristically have a substantially same frequency and at least a same amplitude; the responding signal (42) has a same waveform as the sound signal (32) but both signals are out of phase with a phase difference of substantially 180 degrees; the responding signal (42) and the sound signal (32) propagate in a chosen same region of space: and the responding signal (48) propagates at time that in cohesion with the sound signal in a manner that the responding signal (48) emitted combines with the sound signa' (38) to substantially cancel each other.

2. A sound processing device (100) comprising:

means for receiving sound signal (15): means for processing the waveform of said received sound signal and generating a responding signal (25); and means for emitting the generated responding signal for reducing the volume of the sound signal (5);

characterized in that

the sound signal (36) and the responding signal (46) characteristically consist a substantially same frequency; the responding signal (46) consists an amplitude in the range of less than the sound signal (36) amplitude; the responding signal (46) has the substantially same waveform as the sound signal (36) but both signals (36 & 46) are out of phase with a phase difference of substantially 180 degrees; the responding signal (48) and the sound signal (38) propagate in a chosen same region of space; and the responding signal (48) propagates at time that in cohesion with the sound signal (38) in a manner that the emitted responding signal (48) combines with the sound signal (38) to substantially reduce the audibility of the sound signal.

3. A sound processing device (100) comprising:

means for receiving sound signal (15); means for processing the waveform of said received sound signal and generating a responding signal (25); and means for emitting the generated responding signal for altering the waveform of the sound signal (5);

characterized in that

the sound signal (34) and the responding signal (44) characteristically consist a substantially same frequency; the responding signal has the substantially same waveform as the sound signal (34) but both signals (34 & 44) are substantially out of phase; the responding signal (48) and the sound signal (38) propagate in a chosen same region of space; and the responding signal (48) propagates at time that in cohesion with the sound signal (38) in a manner that the emitted responding signal (48) combines with the sound signal (38) to substantially alter the waveform of the sound signal (38).

4. A sound processing device (100) as defined in any one of the claims 1 to 3, wherein the sound signal (385) corresponds to voice signal (38) being produced by the vocal cords as a person speaks.

5. A sound processing device (100) as defined in any one of the claims 1 to 3. wherein the means for receiving sound signal (15) is disposed in an optimal position close to a source of the sound signal.

6. A sound processing device (100) as defined in the claim 5, wherein the means for receiving sound signal (15) is a plurality of microphones (15a) for use of receiving sound signal (38) from the source of the sound signal.

7. A sound processing device (100) as defined in any one of the claims 1 to 3 further comprising a plurality of processing units which capture the received sound signal (38). collects data of the amplitudes and frequencies of the sound signal (38), and processes the received sound signal and to generate the desired responding sound signal.

8. A sound processing device (100) as defined in any one of the claims 1 to 3. wherein the means for emitting the responding signal (5) is a plurality of speakers (5 a) characterized in that the speakers (5a) are positioned optimally to the source of the sound signal.

9. A sound processing device (100) as defined in any one of the claims 1 to 3. wherein the means for emitting the responding signal (5) is a plurality of speakers (5e) characterized in that the speakers (5e) are positioned at the perimeter of an area enclosing those engaged in a conversation to eliminate only the voice signals (38) transmitted outward of the area perimeter.

10. A sound processing device (100) as defined in the claim 4, wherein the sound processing device is installed in a mobile phone; a primary responding signal is emitted to eliminate, alter or reduce the volume of the voice signal generated by the mobile phone user while conversing to the other contacted user; and a secondary responding signal is emitted to eliminate, alter or reduce the volume of the voice signal of the other contacted user emitted by the mobile phone user.

11. A sound processing device (100) as defined in any one of the claims 1 to 3, wherein the sound processing device (100) is adapted intc the mobile phone hands free kit (70) whereby the means for receiving sound signal (38) employs the sound receiver (15b) of the hands free kit (70) and the means for emitting the generated responding signal (5) is mounted at the hands free kit (70).

12. A method of cancelling a sound signal comprising:

receiving a sound signal (38): processing the sound signal (38); generating a responding signal (48) which has characteristics that substantially eliminate the sound signal (38); and emitting the responding signal (48) to eliminate the sound signal;

wherein

the characteristics include the sound signal (32) and the responding signal (42) having a substantially same amplitude and a substantially same frequency; the responding signal (42) has a same waveform as the sound signal (38); the phase difference between the sound signal (32) and the responding signal (42) is substantially 180 degrees; and both signals (32 & 42) travel in a region of time and space that allows both signals (32 & 42) to combine and cancel out each other.

13. A method of reducing the audibility of a sound signal:

receiving a sound signal (38); processing the sound signal (38); generating a responding signal (48) which has characteristics that substantially reducing the volume of the sound signal (38); and emitting the responding signal (48) for substantially reducing the audibility of the sound signal (38);

wherein

the characteristics include the sound signal (36) and the responding signal (46) having a substantially same frequency; the responding signal (46) has a same waveform as the sound signal; the phase difference between the sound signal (36) and the responding signal (46) is substantially 180 degrees; the responding signal (46) consists an amplitude in the range of less than the sound signal (36) amplitude; and both signals (38 & 48) travel in a region of time and space that allows both signals (38 & 48) to combine and subsequently reduce the volume of the sound signal (38).

14. A method of altering a sound signal comprising:

receiving a sound signal (38); processing the sound signal (38); generating a responding signal (48) which has characteristics that substantially alter the waveform of the sound signal (38); and emitting the responding signal (48) for said alteration:

wherein

the characteristics include the sound signal (34) and the responding signal (44) having a substantially same frequency; the responding signal (44) has the substantially same waveform as the sound signal (34); the sound signal (34) and the responding signal (44) are substantially out of phase: and both signals (38 & 48) travel in a region of time and space that allows both signals (38 & 48) to combine and alter the waveform of the sound signal (38).