MXPA97007435A - Peripheral of intelligent acoustic systems - Google Patents

Abstract

The present invention relates to a personal computer (PC) incorporating a speaker / microphone peripheral that includes an acoustic echo canceller based on the signal processor (DSP) and supports a plurality of operating nodes. One of the nodes is video / telecommunications. In this mode, the active acoustic echo canceller and the microphone / speaker peripheral provide a monaural dual microphone and horn for use in video, video communications, internet telephony, etc. Another mode of operation is a multimedia mode, or wide band stereo. In this multi-media mode, the acoustic echo canceller is deactivated and the stereo speakers provide high fidelity stereo output signals. In addition, in this last assembly, an optional subwoofer can be additionally coupled to the stereo speakers. The horn / microphone peripheral switches between the operating nodes upon detection of a predefined sequence of dual tone mluti-frequency (DTMF) digits. The DTMF sequences are reproduced from wave type files stored in the

Description

PERIPHERAL OF INTELLIGENT ACOUSTIC SYSTEMS CROSS REFERENCE TO RELATED REQUESTS The related matter is described in the US patent applications, commonly assigned copendientes, of Yu with the title "Video and Audio Answering Machine" (Machine of Video and Audio Answering Machine), No of Series 08/690431, filed on July 26, 1996, by Brown et al, entitled "Intelligent Acoustic Systems Peripheral" (Serial of Intelligent Acoustic Systems), Serial No. XXX, filed on October 4, 1996; and that of Brown et al. entitled "Intelligent Acoustic Systems Peripheral" (Serial of Intelligent Acoustic Systems), Serial No. XXX, filed on October 4, 1996. BACKGROUND OF THE INVENTION The present invention relates to acoustic systems for use in personal computers, work stations or telephone systems. In today's world, the availability and access to "multi media" communications is growing. For example, the ability to see and hear someone while communicating over telephone lines is not limited to specially designed video phones. This technology is now available through the use of a personal computer (PC), or workstation, specially configured with a camera, a video capture board and a speaker / microphone. By REF: 25477 example, see patent of the U.S.A. No. 5,524,110 granted on June 4, 1996, and with the title "Conferencing over Multiple Transports" and the "ProShare" system commercially available from Intel Corporation. These systems allow parties that call and call both to see and hear each other. In fact, the US patent. above mentioned describes other types of PC-based service such as video answering machines. In these PC-based or video-conferencing video telephony systems, a separate dedicated microphone and speaker system is employed to allow full hands-free duplex voice communications between the calling party and the called party during the video call . Unfortunately, if a user of a PC that incorporates physical equipment with video telephony also wants to subsequently listen to stereo music played from a peripheral CD-ROM of the PC, an extra set of speakers is required. In other words, if a user wishes to have both PC-based video communications and listen to computer-based multimedia applications - separate speaker structures are required. COMPENDIUM eg THE INVENTION A sound system that uses in-band signaling to select one of a number of operating modes.

In one embodiment of the invention, a PC incorporates a microphone / speaker peripheral that includes an acoustic echo canceller based on a digital signal processor (DSP) and supports a plurality of operating modes. One is a telecommunications / video mode. In this mode, the acoustic echo canceller is activated and the microphone / speaker peripheral provides a monaural dual microphone and horn for use in video communications. Another mode of operation is a broadband or multi-media stereo mode. In this multi-media mode, the acoustic echo canceller is deactivated and the stereo speakers provide high fidelity stereo output signals. In addition, in this last setup, an optional subwoofer can be additionally coupled to the stereo speakers. The horn / microphone peripheral switches between operating modes upon detection of a predefined sequence of multi-frequency dual tone (DTMF) digits. The DTMF sequences are reproduced from wave-type files stored on the PC. BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 shows a system-level block diagram illustrating a microphone / speaker peripheral, in accordance with the principles of the invention? FIGURE 2 shows an illustrative diagram of a microphone / speaker peripheral according to the principles of the invention; FIGURE 3 shows an illustrative block diagram of a microphone / speaker peripheral according to the principles of the invention; FIGURE 4 shows a block diagram at the level of a more detailed illustrative circuit of a microphone / speaker peripheral according to the principles of the invention; and FIGURE 5 shows an illustrative method for use in detecting a signal based on in-band DTMF; FIGURE 6 shows an illustrative software architecture used in implementing steps 505 and 510 of FIGURE 5; and FIGURES 7 and 8 show examples of using an "applet" (small application, utility program) to change operating modes. PffSRTP TQW PKT? T.TAPA As used herein, the term "telecommunications" means physical equipment and / or software involved in communications (video and / or audio) between at least one calling party and a called party. In comparison, the term "computer-based multi-media applications" means all other physical equipment and / or software that cause acoustic signals to be generated by a speaker system or received by a microphone. For example, the aforementioned reproduction of a song from a CD-ROM peripheral of a computer is considered a computer-based multimedia application notwithstanding the fact that essentially this particular application only plays audio from the CD-ROM. Also, it should be noted that since the inventive concept relates to an acoustic system operating in a plurality of different modes such as telecommunication mode, or multimedia mode, the specific details regarding the hardware / software are not described here. of telecommunications or particular multi-media applications since such descriptions are not necessary to understand the inventive concept. A system-level block diagram illustrating a horn / microphone peripheral according to the principles of the invention is illustrated in FIGURE 1. The PC 100 comprises the CPU 130 and the display 110, both of which represent the element core of a PC as is known in the art. For example, CPU 130 is a Pentium-based processor and includes: volatile and non-volatile memory such as read-only memories (ROM) and random access memory (RAM), non-removable magnetic media such as hard disk space as known in the specialty and ability to accommodate removable media such as floppy disk drives, CD-ROMs, etc. In addition, the CPU 130 includes a keyboard (not shown) and other pointing devices such as the mouse. The display 110 represents a monitor for displaying information as is known in the art and the video system for controlling the monitor. The CPU 130 is considered to operate a disk-based operating system such as Windows 95 available from Microsoft Corporation. Finally, the sound card 125 for example is a sound card compatible with Soundblaster to provide audio signals (or online signaling) 136 to the horn system 135 and to receive the microphone signal 137 (or line output signaling) . Although not illustrated separately in Figure 1, the horn / microphone system 135 includes a pair of speakers and a directional microphone included within one of the speaker enclosures. The remaining elements of the PC 100 for purposes of this example are considered part of the video processing system coupled to the CPU 130 via the duct 131. The video processing system includes the camera 105, video communications board 115 and interface of communications 120. The camera 105 and the video communications board 115 are part illustrative of the "Desk Top Video Phone product" of the Intel corporation and also known as "ProShare". The communication interface 120 is representative of any of a number of communication interfaces such as an analog modem, ISDN, or local area network interface (LAN = local area network). The communication interface 120 transmits and receives from a far end, image and audio information that incorporates a digital signal through the communication channels 17. The far end can be located in a switched network (such as the public switched telephone network (PSTN) )), LAN, etc. (not shown). Turning now to FIGURE 2, the last one shows a graphic representation of the illustrative modality described here. The speaker / microphone system 135 includes a main speaker 134, satellite speakers 133 and an optional subwoofer 132. The microphone 139 is mounted within the main speaker 134. The microphone 139 is preferably a directional microphone such as the microphone. DM 1000 available from Lucent Technologies. The directional microphone is physically configured to reduce the acoustic coupling of the speakers. (Additionally, the directional microphone technology is described in U.S. Patent No. 5,226,076, issued to Baumhauer et al. On July 6, 1993, entitled "Directional Microphone Assembly" (Directional Microphone Structure).; and the US patent. No. 5,121,426 issued on June 9, 1992, granted to Baumhauer et al., Entitled "Loudspeaking Telephone Station Including Directional Microphone") (Telephone Station With Speaker Including Directional Microphone).

An illustrative block diagram of the horn / microphone system 135 is illustrated in Figure 3. It will be noted that to highlight the inventive concept, FIGURE 3 represents a simplified block diagram which will be described below. A more detailed circuit-level block diagram of the components of the horn / microphone 135 is illustrated in FIGURE 4. Aside from the inventive concept, the components illustrated in FIGURES 3 and 4 are well known and will not be described in detail. In accordance with the principles of the invention, the horn / microphone system 135 operates in different modes of operation.

The latter are determined by DSP 250, which at least partially serves as a microphone / horn system controller 135. Although numerous different types of modes can be defined for the horn / microphone system 135, for the purposes of this description, it is considered that the following illustrative modes exist: Multi-media operation mode narrowband telecommunications broadband telecommunications Table One The transition between the previously defined modes of operation is described further below. (In this context, the mode of operation represents a "state" of the horn / microphone system 135. This state can be represented, for example by a value of a variable or predetermined record within DSP 250). Each of these modes will now be described briefly. The "multi-media" mode of operation provides a broadband stereo capability. This mode of operation allows the horn / microphone system 135 to support "computer-based multi-media applications" such as the aforementioned CD-ROM player. In this operation mode, echo cancellation is disabled. The narrowband telecommunications mode as the name implies, is useful for communications between a calling party and a called party. In this mode, the audio bandwidth is standard telephony: 3.2 kHz (kilo-hertz) and echo cancellation is activated. The horns provide a monophonic or mono operation. Broadband telecommunications mode is similar to narrowband telecommunications mode except that the audio bandwidth extends to 7 kHz. In this operation mode, echo cancellation is activated. The horns provide a mono or monophonic operation. When energizing the DSP 250, it examines the state of two bridge hands (not shown) to determine the predefined operating mode. (Obviously, these two bridge needles provide a maximum of four predefined operating modes, however, only three are available according to Table One). It is considered that the multi-media operation mode is the predefined mode. As can be seen from the above, the modes of operation can be characterized as either "multi-media" or "telecommunications", with the essential difference that an echo canceller is activated in a telecommunications mode. As such, the initial description of the elements in FIGURE 3 will be in the context of either the multi-media mode or telecommunications mode of operation. The switch 265 of FIGURE 3 is under the control of DSP 250 by the control signal 251. The latter causes the switch 265 to provide different signaling as a function either in a multi-media mode or telecommunications mode. (Alternately, switch 265 is known as a "selector" as it is known in the art). In the context of this description, the control signal 251 is considered to represent a binary digit ("bit"), wherein one value of the binary digit is associated with a multi-media operation mode and the other value of the binary digit it is associated with a mode of telecommunication operation. (Additional modes can be easily allowed by simply enlarging this control duct to include more bits.) However, as noted in Table One above, the number of operating modes is not restricted by the number of control bits in this control duct). In a multi-media mode of operation, the switch 265 a) couples the output signaling 241 to the switch 270 and b) generates microphone signal 137 from the output signaling of the microphone system 255. In contrast, in an operation mode of telecommunications, the switch 265 a) couples the output signal of the amplifier / codec 231 to the switch 270 and b) generates a microphone signal 137 from the amplifier / codec output signal 261. In light of the above operational modes, it is now provides a brief review of the operation of the horn / microphone 135. Audio signals 136 apply to the balance power amplifier (s) 205, which provide output signals to a multi-media processing portion and a processing portion. of telecommunications. The multi-media processing portion comprises one or more multi-media amplifier systems 210, adder 215, subwoofer 225, low frequency loudspeaker 240 and switches 220 and 235. In contrast, the portion of telecommunications processing comprises codec / amplifier 230 and a portion of DSP 250 (described below). As described above, depending on the operational mode, either output signaling from the telecommunications processing portion or the multi-media processing portion will be selected by the switch 265 for application to the switch 270. (Again, to avoid confusion , it should be remembered that FIGURE 3 is a simplified block diagram of FIGURE 4. For example, the balance power amplifier (s) 205 is representative of two balance supply amplifiers for the left and right channel as illustrated in FIG. Figure 4. It will be noted that the control signal 251 is also illustrated as applied to loudspeaker detection circuits 245. In effect, the control signal is subjected to logic operation "0" (ORed) with signaling from the control circuits. 245 hearing aid detection to further disconnect the subwoofer 225 during telecommunication mode, in any one mode of multi-media or a telecommunications mode, the signaling applied to the switch 270 generates acoustic signals in one of two ways, depending on the presence of hearing aids 275. When the hearing aids 275 are not present, the acoustic signals are generated by the loudspeakers. controllers 280 and (if present and activated) the subwoofer 225. In contrast, when the hearing aids 275 are present, the switch 270 switches the audio output from the speakers / controllers 280 to the hearing aids 275. In addition, circuits for loudspeaker detection 245 disconnect the subwoofer 225 from the audio system, by means of the switch 220, and cause the output signaling of the multi-media amplifier system 210 to derive the low frequency peak element 240 via the switch 235. (It will be noted that the switch 270 is representative of the traditional mechanical switching element currently employed to switch between the Headphone outputs and speaker outputs. For example, the physical connection of a speaker plug commutates the state of the switch 270. In contrast, loudspeaker detection circuits 245 comprise an additional sensing element that electrically senses the presence of the horns 275). As can be seen from FIGURE 3, the loudspeaker circuits 245 provide a signal to the DSP 250. This signal alerts the DSP 250 when the loudspeakers are inserted or removed, such that in a telecommunications mode, for example, a band. narrow or wide band, the echo canceller coefficients are reinitialized or re-trained due to a different acoustic transfer function. . Now moving to the microphone / speaker microphone 135, similar generalizations can be made regarding a multi-media portion and a telecommunications portion. The microphone system 255 applies signaling to the codec / amplifier 260. The latter element, together with a portion of DSP 250 (described below) represents the telecommunications portion. In terms of a multi-media portion, the microphone system 255 simply directly applies an output signal to the switch 265. The latter as noted above, selects either the amplifier / codec output signal 261, or the signal from output of the microphone system 256, as the microphone signal source 137 according to the respective mode of operation. Turning now briefly to FIGURE 4, the latter shows a more detailed block diagram of the components of the horn / microphone 135. Similar numbers in FIGURE 4 refer back to the numbers used in FIGURE 3. Numbers of the type " 210-1"and" 210-2"reflect the fact that at present, the left and right channels are processed separately as illustrated. Although not shown for simplicity, the power for the unit is supplied with a wall-mounted transformer. In order to support a telecommunication mode of operation, DSP 250 in conjunction with codec amplifiers 230 and 260 comprises an echo canceller sub-band to reduce horn-to-microphone coupling. The audio bandwidth is standard telephony: 3.2 kHz (kilo-hertz). The acoustic echo canceller subband technology is well known as represented by the US patent. No. 5,548,642, granted on August 20, 1996 and entitled "Optimization of adaptive filter tap settings for sub-band acoustic echo cancelers in teleconferencing" (Optimization of adaptive filter derivation adjustment for sub-band acoustic echo cancellers in teleconference ). Although a full-band echo canceller is an alternate approach, a subband echo canceller converges faster in the presence of speech). In broadband telecommunications mode, the audio bandwidth is increased to 7 kHz. As a result of the foregoing, a multi-media operation mode provides audio-stereo capability through the speakers / controllers 280 for any computer-based multi-media applications. In contrast, a telecommunications mode of operation provides a monaural dual microphone and horn with acoustic echo canceller based on DSP. As noted above, a predefined operating mode is provided by a set of bridges (not shown). However, during operation, a simple method is proposed to allow any application or the user to switch between the various modes of operation. In particular, the DSP 250 checks the received audio signal (via codec / amplifier 230) for a specific DTMF (multi-frequency-of-tone-dual) sequence, which controls the mode and operation of the horn / microphone 135. In other words, band signaling is used to switch modes since the audio or acoustic signals themselves carry the control signaling. (Generally speaking, in-band signaling can be defined as using a portion of the bandwidth of a signal that contains information to carry signaling information). Advantageously, in-band signaling does not require an additional interface between the computer and speaker / microphone 135 apart from line input and audio interface line output signals. In fact, in-band signaling allows the use of stored wavewave audio files (".wav") as it is known in the specialty). As such, any application that has the ability to deal with audio signals can perform the required switching without the use of specialized controllers. This method will also be independent of platform and operating system. Once energized, three basic band signals are used to access each of three modes of operation. When receiving an audio signal that contains one of three signals in band, the operating horn / microphone 135 changes to the respective operating mode. To avoid foreign state changes, but allow reliable detection of these in-band signals in the presence of relatively large amounts of other signals (such as can currently be reproduced when requesting mode change), some special considerations should be given to the design of the signals and of the decode used to detect. Illustratively, the use of the DTMF digits A, B, C and D constitute the basic symbols of the messages used for in-band signaling. (DTMF signaling is well known and will not be described in detail.) Generally speaking, DTMF digits defined by industry or symbols are made up of a pair of frequencies known as row frequency and column frequency (also known as low frequency and high frequency). -frequency) that constitutes a table of permissible frequency pairs to use in generating DTMF tones). As is known in the art, in normal DTMF signaling over a telephone, the microphone is usually silent. This results in a pure set of tones with relatively small energy outside the expected high and low DTMF tones. Most DTMF decoders measure both high and low energy tones as well as energy at other frequencies to determine if the signal is sufficiently "pure". This is to avoid close spoken speech as a condition where speech is confused by a digit DTMF. In contrast, the horn / microphone 135 receives the signaling information in band via line access port or line input. As such, the reception of DTMF signals can occur in the presence of other signals (for example if a song is currently being played on a CD-ROM) and another reliable DTMF detection method should be employed to insure against the occurrence of closed speech. This new reliable DTMF detection method will be described below. To avoid close speech broadcast using band signaling, a strict four-digit DTMF sequence is employed. The first three DTMF digits with a strict synchronization ratio are used as a preamble or spindle to activate the reception of the fourth digit DTMF. This fourth digit then determines the appropriate mode of operation. Although there may be several "false detections" of DTMF digits, or even the intentional use of DTMF digits by applications for other purposes, laboratory tests suggest that the occurrence of the exact sequence with exact timing ratios is not likely. Illustratively, the DTMF pre-amber or spindle is the DTMF "CAD" sequence at 100 millisecond (ms) intervals without interleaved silence. The fourth digit DTMF is already A, B or C. This last digit DTMF determines the appropriate state. The entire sequence takes exactly 400 ms (four DTMF digits multiplied by 100 ms per digit). (It should be noted that more than one type of head can be used, with for example different heads indicating different types of operations as evidence, etc.). A summary of the associated DTMF modes and sequences is illustrated in Table Two, below. DTMF Sequence Moflo fle Operation EACH narrowband telecommunications CADB multi-media CADC broadband telecommunications Table Two A method to be used in a DTMF detection system is illustrated in FIGURE 5. This method is implemented using DSP 250 and codec / amplifier 230 In step 505, DSP 250 checks the power signal for a DTMF symbol. Upon detection, DSP 250 goes to step 510 to compare the three previous DTMF symbols (received in the previous 300 ms) against the predefined head. If there is no correspondence, DSP 250 returns to step 505 to verify the next DTMF digit. On the other hand, if there is correspondence, DSP 250 switches to the respective mode in step 515 using the DTMF symbol currently received. The respective modes are indicated in Table Two (above). As previously described, each mode causes DSP 250 to alter the signal processing of the audio and microphone signals. For example, the multimedia mode causes the DSP 250 to control the switch 265 to provide audio from the multi-media portion of the speaker / microphone 135. This turns off or deactivates the echo canceller function that is provided by the DSP 250 and in this way it cancels echo cancellation of the audio signal that is provided to the speakers. Further, in this mode the microphone signal is taken from the microphone system 255 of FIGURE 3 (or alternatively from FIGURE 4). As noted, the DTMF detection is provided by DSP 250 and codec / amplifier 230. The software coding of the DTMF detection system can be divided illustratively into four basic blocks as illustrated in FIGURE 6. These four blocks correspond to steps 505 and 510 of FIGURE 5. DSP 250 implements a in-band receiver as a sub-routine that is requested once every 125 microseconds, in either an 8K sample operation mode or a 16K sample operation mode. The sub-routine returns the value or each sample period if nothing has been detected. A value of 1 to 3 is returned when the CADA-CADC sequences have been detected, respectively. The same value will be returned for each sub-routine call for a period of at least 25 ms and possibly up to approximately 100 ms at the end of each detected signal. This value can be used by the DSP code to make the changes in appropriate state. The first block 605 comprises the energy detection filters. These consist of a bank of five elliptical IIR IIR filters (infinite impulse response filters) at the fourth column frequency and the fourth row frequencies of a DTMF table. This stage also provides some loss to help avoid saturation. The specification is for a bandwidth of 20 Hz centered at each DTMF frequency with at least 40 dB rejection at 100 Hz away from each center frequency. The next block, 610, provides rectification and low pass filtering along with additional loss. This provides a signal that corresponds to the envelopes of the five filters. The decoder block 615 is the third block. This block compares the outputs of low pass filters to a threshold. This threshold has both fixed and variable components to allow a wide dynamic range of power signals. The variable component is the sum of the three lowest values of the low pass filters. To this a fixed component is added to adjust a minimum permissible threshold level. Ensures that both the row and column signals corresponding to A - D are valid. This block is implemented as a separate sub-routine and runs only in 25 ms intervals. The final block 620, does string decoding. It searches in the last 300 ms of outputs of the decoder block and determines if the appropriate sequence of signals has been seen with the appropriate synchronization ratio, ie the spindle. If this is true, then the appropriate number, 1 to 3, is returned depending on the current stream decoded.

The band signals initially have an amplitude of -16 dB relative to the peak signal level of analog / digital (A / D) and digital / analog converters. The symbols should be continuous without instantaneous phase changes when moving from one symbol to another at either the high frequency or the low frequency. As noted above, changing the mode can be done by simply playing a "wave file" that generates the appropriate DTMF sequence. This wave file can be played in any number of ways by the user. For example, a small program or "applet" can be used to switch modes. Considering a Windows 95 operating system (with a mouse associated as pointing device) an icon representing this applet is present in the taskbar. The selection of this icon by pressing the right-hand button on the mouse causes a menu to appear, this menu that appears allows the user to select the desired mode. A select menu item causes the appropriate band signal to be produced. Illustrative views of this desktop control are illustrated in FIGURES 7 and 8. Alternatively, the application itself may cause the appropriate band signal to be generated. For example, an application program can play the appropriate wave file at startup and restore the computer back to the previous state upon exiting. For example, when you run an application that allows video conferencing, the video conference application can first play a wave file to switch the speaker / microphone system 135 to a telecommunications operation mode. When it is finished, and just before leaving, this same application can play a wave file to restore the computer to a multi-media operation mode - all done without user intervention. It should be noted that according to one feature of the invention, the use of two horns in a video conference assembly divides the mono signal. (Considering of course that the horns are physically arranged properly). The net effect from a human factors point of view is a centering of the acoustic image. It is further proposed that the well-known "Haas effect" (also known as the "precedence effect") is used by DSP 250 to reduce power to the main speaker 134, however retain a focused acoustic image. In particular, the microphone 139 is more. close to the main speaker 134, since both are incorporated within the same enclosure. As a result, the echo canceller has, so to speak, to work harder to remove the echoes. However, when purging energy to the satellite horn 133 and then using the Haas effect - echo cancellation is improved and the acoustic image is still centered. (As defined in the "Audio Dictionary" by Glenn D. White, University of Washington Press, 1987, the Haas effect also called the precedence effect is related to the location of the apparent sonic image when the same signal is presented to both ears at slightly different times). In other words, providing more power to the satellite horn moves the off-center acoustic image to the satellite horn, however, adding an experimentally determined time delay to the satellite horn path moves the acoustic image back to the center. The foregoing merely illustrates the principles of the invention and it will be appreciated that those skilled in the art will be able to design numerous alternate assemblies or structures which, although not explicitly described herein, incorporate the principles of the invention and are within their scope and spirit. . For example, other applications of the inventive concept are possible such as hands-free telephony which provide high-quality digital multi-media content over LAN wiring or twisted pair. Also the inventive concept is equally applicable to a sound system with different operating modes. Undoubtedly, the inventive concept can be applied by changing the mode or state of the computer system or equivalently another component of the computer system. As used herein, "changing the mode of the computer system" means changing the mode of, for example, the motherboard or main card or other component of the computer system, for example another type of interface card. Also, although the above embodiment is illustrated in the context of in-band signaling in the context of an audio signal, other forms of signaling can be employed such as coupling the speaker system through the keyboard connector, wherein a particular set of Key commands will be used to indicate the changes described above. Alternatively, mode information can be sent directly to a speaker system using the "universal serial duct" (USB) currently proposed in the industry to attach peripherals to a computer. In addition, the aforementioned echo canceller sub-system employed in full duplex voice communications, can be located on a PC sound card, where it can be activated or deactivated according to the principles of these inventions. It is noted that in relation to this date, the best method known to the applicant to carry out said invention, is that which is clear from the present description of the invention. Having described the invention as above, property is claimed as contained in the following:

Claims (49)

1. CLAIMS 1. An improved apparatus for providing acoustic signals, characterized in that the improvement comprises: a sound system that uses in-band signaling to select one of a number of operating modes. The apparatus according to claim 1, characterized in that the operating modes include at least one mode of telecommunications and one mode that is not telecommunications. 3. The apparatus in accordance with the claim 1, characterized in that the sound system further comprises a processor that responds to the signaling in band to select the operating mode for the sound system. The apparatus according to claim 3, characterized in that the processor receives the signaling in band via an audio line input interface. The apparatus according to claim 3, characterized in that the in-band signaling comprises a predefined sequence of dual-tone multi-frequency (DTMF) signals and the processor further comprises a DTMF detector, to detect the predefined sequence of the signals of DTMF. The apparatus according to claim 3, characterized in that the in-band signaling comprises a predefined sequence of DTMF signals and the processor further comprises: a DTMF processing element that responds to a received signal to provide an estimate of a received DTMF signal in a time interval, T; and a sequence detector responsive to N estimated DTMF to select one of a number of operating modes where N > 0. 7. The apparatus in accordance with the claim 6, characterized in that the sequence detector responds to the last received N DTMF estimates to select one of the number of operating modes. The apparatus according to claim 6, characterized in that the sequence detector responds to a previous K estimated DTMF received to correspond to a predefined preamble and then selects one of a number of operating modes as a function of the N * "symbol DTMF received subsequent to a preamble correspondence, wherein K < N. 9. The apparatus according to claim 1, characterized in that the signaling in band is an electrical representation of an acoustic signal. because it comprises: a structure of horns to provide acoustic signals, and a processor for detecting from an electrical representation of the acoustic signals, signaling in band to select one of a number of operating modes for the sound system. 11. The apparatus according to claim 10, characterized in that the processor controls the speaker structure to produce the acoustic signals. The apparatus according to claim 10, characterized in that the operating modes include at least one telecommunication mode and one non-telecommunication mode. The apparatus according to claim 10, characterized in that the speaker structure comprises a main horn mounted in a main horn housing and a satellite horn mounted in a satellite horn housing and wherein the processor is incorporated within the housing of the horn. main speaker. The apparatus according to claim 12, characterized in that the main horn housing incorporates a line access port for audio interface and wherein the processor receives the in-band signaling through the in-line access port. .fifteen. The apparatus according to claim 10, characterized in that the processor is included in a sound card for insertion into a work station. The apparatus according to claim 10, characterized in that the in-band signaling comprises a predefined sequence of dual tone multi-frequency (DTMF) signals and the processor further comprises a DTMF detector for detecting the predefined sequence of DTMF signals. The apparatus according to claim 10, characterized in that the in-band signaling comprises a predefined sequence of DTMF signals and the processor further comprises: a DTMF processing element that responds to a received signal to provide an estimate from a received DTMF signal in a time interval T; and a sequence detector that responds to N DTMF estimates to select one of the number of operating modes where, where N > 0. The apparatus according to claim 17, characterized in that the sequence detector responds to the most recent N DTMF estimates to select one of the number of operating modes. 19. The apparatus in accordance with the claim 17, characterized in that the sequence detector responds to a previous K of the received DTMF estimates to correspond to a predefined preamble and then chooses one of a number of operational modes as a function of the N * "iBβ DTMF symbol received subsequent to a corresponding preamble, wherein K < N. 20. An improved station for providing telecommunications and multi-media applications based on computer, characterized the improvement because it comprises: a horn / microphone structure that responds to signaling in band to select one of a number of operating modes for supporting computer-based telecommunications and multi-media applications 21. The apparatus according to claim 20, characterized in that the in-band signaling is transported via an in-line access port of the horn structure / 22. The apparatus according to claim 20, characterized in that the signaling n in band comprises a predefined sequence of multi-frequency signals dual tone (DTMF) and the horn structure / microphone further comprises a DTMF detector for detecting the predefined sequence of DTMF signals. 23. The apparatus according to claim 20, characterized in that the in-band signaling comprises a predefined sequence of DTMF signals and the horn / microphone structure further comprises: a processing element that responds to a received signal to provide an estimate of a DTMF signal received in a time interval, T; and a sequence detector that responds to N DTMF estimates to select one of a number of operating modes, wherein N > 0 24. The apparatus in accordance with the claim 23, characterized in that the sequence detector responds to the most recent N DTMF estimates to select one of the number of operating modes. 25. The apparatus in accordance with the claim 23, characterized in that the sequence detector responds to a previous K of the received DTMF estimates to correspond to a predefined preamble and then chooses one of the number of operational modes as a function of the N * ßl "° of DTMF symbol received subsequent to a correspondence of preamble, wherein K < N. 26. An improved computer system adapted to execute programs such as programs related to telecommunications and other programs not related to telecommunications, wherein the improvement is characterized because it comprises: a sound system that responds signaling in acoustic band to choose one of a number of operating modes, where at least one operating mode is used for programs related to telecommunications and another operating mode - is used for programs not related to telecommunications. with claim 26, characterized in that the signaling in band comprises a sec The predefined frequency of dual tone multi-frequency signals (DTMF) and the sound system further comprises a DTMF detector, to detect the predefined sequence of DTMF signals. 28. The apparatus in accordance with the claim 27, characterized in that the in-band signaling comprises a predefined sequence of DTMF signals and the sound system further comprises: a processing element that responds to a received signal to provide an estimate of a DTMF signal received in a time interval, T; and a sequence detector that responds to N DTMF estimates to select one of a number of operating modes where N > 0. 29. The apparatus according to claim 28, characterized in that the sequence detector responds to the most recent N of the DTMF estimates to select one of the number of operating modes. 30. The apparatus in accordance with the claim 28, characterized in that the sequence detector responds to a previous K of received DTMF estimates, to correspond to a predefined preamble and then selects one of the number of operational modes as a function of the N * "1" 0 of the DTMF symbols received subsequent to a correspondence in preamble, where K <; N. 31. A computer system characterized in that it comprises: a processor controlled by stored programs; a sound system; and a storage system; wherein the processor controlled by stored program causes at least one file to represent acoustic information that is retrieved from the storage system to be reproduced by the sound system, such that when producing the sound system it switches to one of a number of operational modes. The apparatus according to claim 31, characterized in that the processor controlled by stored program causes the recovery of acoustic information as a result of which a user chooses a program for execution. 33. The apparatus according to claim 32, characterized in that the selected program is an applet @ stored in the storage system. 34. The apparatus according to claim 32, characterized in that the selected program is an application program stored in a storage system. 35. Apparatus for use in a computer to control the state of a computer, the apparatus is characterized in that it comprises: a sound system to reproduce acoustic signals; and a processing element for a) detecting control signals in an electrical representation of the acoustic signals, and b) selecting one of a number of operating modes for the computer as a function of detected control signals. 36. The method according to claim 35, characterized in that the control signals are represented by dual tone multi-frequency (DTMF) symbols. 37. A method to use in a computer to control the computer, the method is characterized because it comprises the steps of: reproducing acoustic signals through a sound system of a computer; detecting control signals in the acoustic signals; and selecting one of a number of operating modes for the computer as a function of the detected control signals. 38. The method according to claim 37, characterized in that one operating mode for the computer is a telecommunications mode and another operating mode of the computer is a multi-media mode. 39. The method according to claim 37, characterized in that the operating mode for the computer controls an operating mode of the sound system. 40. The method of compliance with the claim 37, characterized in that the control signals are represented by dual tone multi-frequency (DTMF) symbols. 41. The method according to claim 37, characterized in that the detection step further comprises the steps of: detecting a dual-tone multi-frequency symbol (DTMF) in a time interval; corresponding N detected DTMF symbols with a predefined list of M DTMF sequences, wherein each of the M DTMF sequences comprises N DTMF symbols; and selecting one of the number of operating modes corresponding to the corresponding DTMF sequence. 42. The method according to claim 41, characterized in that the matching stage sets the most recent N of the detected DTMF symbols. 43. The method according to claim 37, characterized in that the detection step further comprises the steps of: detecting a dual-tone multi-frequency symbol (DTMF) in a time interval; K correspond previously detected DTMF symbols with a predefined preamble sequence; and if a correspondence occurs in the previous stage, select one of the number of operating modes corresponding to the current detected DTMF symbol. 44. A method for use in controlling a sound system, the method is characterized in that it comprises the steps of: reproducing acoustic signals by means of the sound system; detect a control signal in the acoustic signals; select an operating mode of the sound system as a function of the detected control signal. 45. The method according to claim 44, characterized in that one mode of operation for the sound system is a mode of telecommunications and another mode of operation for operation in the sound system is a non-telecommunications mode. 46. The method according to claim 44, characterized in that the control system comprises at least one dual tone multi-frequency signal (DTMF). 47. The method according to claim 44, characterized in that the detection step further comprises the steps of: detecting a dual-tone multi-frequency symbol (DTMF) in a time interval; matching N detected DTMF symbols with a predefined list of M DTMF sequences, wherein each of the M DTMF sequences comprises N DTMF symbols; and selecting one of the number of operation modes corresponding to the correspondence DTMF sequence. 48. The method of compliance with the claim 47, characterized in that the matching step corresponds to the most recent N of the detected DTMF symbols. 49. The method of compliance with the claim 44, characterized in that the detection step further comprises the steps of: detecting a dual tone multi-frequency symbol (DTMF) in a time interval; matching K DTMF symbols previously detected with a predefined preamble sequence; and if a correspondence occurs in the previous stage, select one of a number of operating modes corresponding to the current detected DTMF symbol.