Abstract:
In a method and system for controlling voice communication of a first person with at least a second person via a communication network a first microphone receives and converts vocal utterances from the first person to a voice signal. A first processor generates a transmission signal by processing the voice signal. A transmitter sends the transmission signal to a receiver. The receiver generates a listening signal by processing the received signal and transmits the listening signal to a speaker. The speaker converts the listening signal to an acoustic signal to be perceived by the first person. In this method a second processor generates the listening signal from the received signal by branching the voice signal and adding the branched voice signal to the received signal. The branched voice signal may be subjected to variable attenuation and/or amplification before being added to the branched voice signal to the received signal.

Description:
FIELD OF INVENTION 
       [0001]    This invention concerns a procedure and a mechanism to control voice communication, and to use voice communication for teleconferencing, for headphones/earphones or a headset. 
       BACKGROUND OF THE INVENTION 
       [0002]    For voice communication procedures like teleconferencing/videoconferencing when also using a headset with cellular phones or the like, voice quality is an important design criterion. 
         [0003]    If conference participants are located in a loud environment, this can disrupt the conference. This can happen if the participant is taking part in the conference using a cell phone in public, but participants using a headset in a conference environment can also be affected. On the one hand, the participants in the loud environment find it more difficult to understand the content of the conference; on the other hand, the ambient noise is transmitted to the other conference participants. In addition, the participants in the loud environment cannot hear their own voices well, which makes them have to speak louder to overcome the ambient noise. This can cause at least two other disadvantages. For one, speaking louder can result in additional noise, which can be disruptive at the location of the other participant, e.g., in an open-plan office (in an environment with many conference participants, this can also result in everyone attempting to speak louder than the others, and the noise level building up accordingly). For another, it is difficult to discuss confidential and/or commercial matters in publicly accessible buildings or publicly accessible locations, since basically anyone in the vicinity can listen in. The participant&#39;s auditory impression can also be disrupted if the speaker&#39;s own voice is played back to him or her out of the conference system with a certain delay (i.e., “round trip delay”). Echo and hall effects can be created, for example, if the voice signal is output by the conference system via a speaker and picked up by a microphone (acoustic echo), or if signals are simultaneously sent and received by telecommunication equipment (duplex echo). An echo and the resulting disruption gets stronger the louder the participant speaks. 
         [0004]    To minimize the disruption caused to other participants by a participant speaking too loud, it is common for a conference moderator or the participant to manually lower the sound level of the line with the loud environment (i.e., “muting”). This is often a repetitive procedure, and it might have to be adjusted multiple times or constantly. 
         [0005]    To handle disruptive ambient noise, it is common, e.g., for teleconferencing, to output to the ear&#39;s speaker the ambient noise phase shifted by 180° in addition to the conference signal. This cancels out the ambient noise for the ear. Similar solutions have also been developed for listening to music on a plane or in a train car, or for aircraft or helicopter pilot headsets. In the best case, the environment can barely be heard. However, the participant&#39;s voice can also barely be heard, since this type of headset often fits very tightly against the ear and is designed to be soundproof. To hear himself or herself, the participant again attempts to speak very loudly, which leads to the disadvantages described above. 
         [0006]    As described, ambient noise can also be picked up by a participant&#39;s voice microphone and transmitted via the conference system or a telephone system to other participants. A solution to this problem has already been developed for headsets in the mobile communications field, using two directional microphones, for example, arranged in opposite directions (toward the mouth/away from the mouth). The signal-to-noise ratio of the transmission signal is also improved there by compensating for the ambient noise. In this case, the other participants no longer hear the background noise as loudly. However, the participant is still subjected to the loud environment, and the other participants cannot tell that the speaker is speaking so loudly to overcome the ambient noise, and that this person may still have problems following along with the conference due to disruption from the loud ambient noise. 
         [0007]    There is also another problem with a headset. Many headsets are designed for the earpiece to form a soundproof seal to block out the ambient noise. This also makes it necessary to remove the headset to interact with one&#39;s surroundings. The headset is also disruptively large. This means that a compromise must be made to acoustically seal the earpiece so the desired signal does not have to be amplified very strongly, since this amplification is energy-intensive and comes at a cost of battery life. In addition, it is also common here to output the ambient noise with a 180° phase shift, i.e., inverted, which causes the ear to cancel out the ambient noise. 
       SUMMARY OF THE INVENTION 
       [0008]    A function of this invention is to improve voice communication when a speaker is influenced by ambient noise, both for the speaker as well as for the other communication participants. 
         [0009]    The function is achieved with the characteristics of the independent claims. Advantageous refinements and preferred embodiments of the invention are specified in the subclaims. 
         [0010]    One factor of this invention is a proposed procedure for controlling voice communication between a first person with at least a second person via a communication network, whereupon the procedure includes the following steps:
       Receiving the voice signal from a first microphone, which is developed to convert vocal utterances from the first person,   Generating a transmission signal by processing the voice signal,   Transmitting the transmission signal to the communication network,   Receiving a received signal from the communication network,   Generating a listening signal by processing the received signal, and   Transmitting the listening signal to a speaker that is developed to convert the listening signal to an acoustic signal to be perceived by the first person,       
 
         [0017]    whereupon the processing of the received signal to generate the listening signal includes the following steps:
       Branching the voice signal, and   Adding the branched voice signal to the received signal, whereupon the branched voice signal is subjected to a preferably variable attenuation and/or amplification before the addition.       
 
         [0020]    For the purposes of the invention, a microphone is considered any sound-to-signal converter. The voice signal generated using the first microphone reflects utterances from the first person. For the purposes of the invention, transmitting and receiving can be considered both transmitting communications with transmitting and receiving devices as well as coupling signals or line link circuitry. For the purposes of the invention, a communication network can be, but is not limited to, a wired telephone network, a cellular telephone network or another type of radio network, suitable building cabling, a central conference server, etc. For the purposes of the invention, a speaker can be considered any signal-to-sound converter, particularly a headset, earphones, headphones, an in-ear speaker device, etc. The signal processing can be analog or digital, and can use wired circuitry or software-based methods. Variable attenuation or amplification is considered a (frequency-dependent or frequency-independent) decrease or increase in gain through automatic means or manually by a person, particularly the first person. In addition, for the purposes of the invention, branching is considered the forking of a signal path of a physical circuit arrangement or generating a copy of a digital representation of the voice signal. Preferably, the voice signal will be branched as it is received. Alternately, the voice signal can also be branched after any of the processing steps in a processing path between receiving the voice signal and transmitting the transmission signal. 
         [0021]    If the first person&#39;s voice signal is added to the listening signal, the speaker will be able to hear himself or herself. This allows the speaker to speak more quietly, and also establish a certain amount of confidentiality for the conversation, even if the discussion is taking place in public. The environment is disrupted less by the discussion. In addition, conference participants or telephone conversation partners with the first person will no longer be irritated by the first person speaking too loudly. Variability of attenuation and amplification characteristics can also be used to reach a comfortable balance between the received signal and the voice signal. 
         [0022]    Preferably, the processing of the received signal to generate the listening signal in the procedure according to the invention includes the following steps:
       Branching the transmission signal,   Subjecting the branched transmission signal to a preferably variable echo compensation to generate an echo compensation signal matching an anticipated echo of the transmission signal contained in the received signal, and   Subtracting the echo compensation signal from the received signal.       
 
         [0026]    For the purposes of the invention, subtracting a signal can also be considered adding the inverted signal, i.e. the signal phase-shifted by 180°. The echo compensation signal is achieved, for example, by applying a delay and attenuation with preset, configurable, or automatically adjustable parameters, like delay time and attenuation factor, in particular. This can reduce acoustic or device-related echo effects. 
         [0027]    An advantageous refinement of the procedure according to the invention includes the following step:
       Receiving a general ambient signal from a second microphone that is arranged in an environment where the first person is located, and exhibits different sound acceptance characteristics than the first microphone, particularly its sound acceptance direction,       
 
         [0029]    whereupon the processing of the voice signal to generate the transmission signal includes the following step:
       Subtracting the general ambient signal from the voice signal, whereupon the general ambient signal is subjected to preferably variable attenuation before the subtraction.       
 
         [0031]    For the purposes of the invention, an ambient signal reflects an acoustic signal or a noise signal of an environment where the first person is located. For the purposes of the invention, the characterization as a general ambient signal conveys that the ambient signal reflects a noise level prevailing in the environment of the first person without being linked to a specific location. The second microphone can therefore be structurally combined with the first microphone, or structurally separate from the first microphone. In any event, the second microphone is a separate sound-to-signal converter. By subtracting the ambient signal from the voice signal of the first person, ambient noise can effectively be filtered out of the transmission signal. The signal-to-noise ratio of the transmission signal improves. Other communication partners, like any conference participants or telephone partners are no longer disrupted by the noise in an environment where the first person is located. To receive a faithful auditory impression, the ambient noise can only be filtered in part, so that a small portion of the ambient noise is transmitted along and the conversation partner can also adapt to the situation of the first person. The variable attenuation is preferably adjusted automatically by a control unit or manually by the first person. It is also conceivable that the variable attenuation could also be adjusted at an external location like a conference server or the like, if the procedure is used in a conference system. 
         [0032]    In a preferred embodiment of the procedure according to the invention, the processing of the received signal to generate the listening signal includes the following steps:
       Branching the general ambient signal, and   Subtracting the branched general ambient signal from the received signal, whereupon the branched general ambient signal is subjected to preferably variable attenuation before the subtraction.       
 
         [0035]    In this way, the first person is shielded from ambient noise by phase-shifting the general ambient signal by 180° and playing it with the listening signal. The noise perceived from the environment and the inverted ambient signal more or less cancel each other out at the ear of the first person, i.e., where the speaker is located. Also here, the cancellation can be limited to a certain degree, so the first person does not completely lose contact with the environment. This can be important, particularly in traffic or other safety-related situations like in a machine environment, or generally to ensure a realistic perception of the situation. 
         [0036]    In this embodiment, the voice signal and the general ambient signal are preferably generated at essentially the same location, preferably in the vicinity of the first person&#39;s mouth, with different sound acceptance directions for the first microphone and the second microphone. In other words, the voice signal and the general ambient signal should be generated such that the first microphone records voice signals emitted by the first person&#39;s organ of speech together with the ambient sound, while the second microphone converts ambient noise—fading out or shielding the speech sound to the greatest extent possible—to the general ambient signal, whereupon the ambient noise essentially does not contain the first person&#39;s voice. 
         [0037]    Another preferred embodiment of the procedure according to the invention includes the following step:
       Receiving a specific ambient signal from a third microphone, which is in the vicinity of the first person&#39;s ear, particularly closer to the first person&#39;s ear than the second microphone,       
 
         [0039]    whereupon the processing of the received signal to generate the listening signal includes the following step:
       Subtracting the specific ambient signal from the received signal, whereupon the specific ambient signal is subjected to preferably variable attenuation before the subtraction.       
 
         [0041]    By using a specific ambient signal in the vicinity of the first person&#39;s ear, the procedure can differentiate between an ambient sound that prevails at a playback location of the speaker, i.e., the first person&#39;s ear, and ambient sound conditions at the voice recording location where the first microphone records the first person&#39;s voice sound. This can separately optimize an additive fading out of the ambient sound by adding an inverted or 180° phase-shifted ambient signal both for the second person receiving the transmission signal and for the first persons receiving the listening signal. 
         [0042]    For this embodiment, the listening signal and the specific ambient signal are preferably generated at essentially the same location through the speaker/the third microphone, whereupon the sound acceptance direction for the third microphone preferably corresponds essentially with the sound emission direction of the speaker. Ideally, the sound acceptance characteristics of the third microphone match the sound acceptance characteristics of the human ear as closely as possible. This allows the shielding of one of the first person&#39;s ears from ambient noise to be particularly effective so that the received signal and the first person&#39;s own voice signal can be played back with optimal comprehensibility at the location of the speaker, after suitable attenuation of the ambient noise prevailing at the ear. 
         [0043]    In a particularly preferred refinement of the invention, the received signal is processed for each of the first person&#39;s ears separately according to the procedure described above such that:
       The speaker includes a first speaker assigned to the first ear of the first person, and a second speaker assigned to the second ear of the first person.   The listening signal includes a first listening signal to transmit to the first speaker, and a second listening signal to transmit to the second speaker.   The third microphone includes a first third microphone and a second third microphone.       
 
         [0047]    —The specific ambient signal includes a first specific ambient signal generated by the first third microphone, and a second specific ambient signal generated by the second third microphone.
       The first specific ambient signal is preferably variably attenuated and subtracted from the received signal to generate the first listening signal, while the second specific ambient signal is preferably variably attenuated and subtracted from the received signal to generate the second listening signal.       
 
         [0049]    In other words, this embodiment is designed so the listening signal is generated in two channels, i.e., in stereo. Since each ear receives a specific ambient signal, and the respective listening signal is played back inverted, the ambient noise can be faded out optimally for each ear. This allows, for example, a loud conversation taking place predominantly on one side of the first person to be faded out specifically on this side, while a background noise like a busy street that is predominantly on the other side of the first person can be faded out specifically on this side. 
         [0050]    According to another factor, a procedure can be declared to process a received signal to play back in a first channel and a second channel via a headphone device, whereupon each channel is assigned to one side of the headphone device, whereupon the procedure includes the following steps:
       Receiving a received signal,   Processing a received signal to a first listening signal assigned to the first channel, and a second listening signal assigned to the second channel, and   Transmitting the first listening signal to a first speaker of the headphone device, and a second listening signal to a second speaker of the headphone device,       
 
         [0054]    whereupon the step of processing the received signal to generate the listening signal includes the following steps:
       Receiving a first ambient signal from a first microphone that is designed to be in the vicinity of the first speaker or structurally combined with it, and a second ambient signal from a second microphone that is designed to be in the vicinity of the second speaker or structurally combined with it, and   Subtracting the first ambient signal from the received signal in a processing path to generate the first listening signal, and subtracting the second ambient signal from the received signal in a processing path to generate the second listening signal, whereupon the first and the second ambient signals are subjected to preferably variable attenuation before the subtraction.       
 
         [0057]    This can include processing a voice signal recorded by another microphone to generate a transmission signal to be transmitted on a communication network, whereupon the processing of the voice signal includes the following steps:
       Branching the first and/or the second ambient signal, and   Subtracting the branched first and/or second ambient signal from the voice signal, whereupon the first and/or second ambient signal is/are subjected to preferably variable attenuation before the subtraction.       
 
         [0060]    Using the first and/or second ambient signal generated at the speakers of the headphone device makes it possible to forgo the use of another microphone to capture the general ambient sound. The voice signal can then also be received by the communication network such that the audio play back procedure according to this factor can also be used as a procedure to control voice communication. 
         [0061]    In all of the previously described embodiments of the invention, the processing of the voice signal to generate the transmission signal can include automatic gain adjustment/control. 
         [0062]    Depending on the type of the transmission of the received signal, perhaps if the two channels are modulated or duplexed into a single carrier signal, it may be necessary to split (separate) the received signal into two listening channels. However, the received signal can also be received in two channels, perhaps at two different frequencies or via separate cables or cable wires, whereupon the received signal of the first channel is processed to generate the first listening signal, while the received signal of the second channel is used to process the second listening signal. 
         [0063]    Another embodiment of the invention provides a mechanism to control voice communication, whereupon the mechanism is designed and equipped to execute the procedure described above. The function of this invention is solved by this mechanism for the same reasons as specified above for the procedure according to the invention. The equipment to execute the procedure can, for example, take the form of an appropriately programmed computing unit, or appropriately designed and wired hardware. 
         [0064]    According to another embodiment of this invention, the mechanism described above is used for a speaking/listening unit that is selected from the group including at least a radiotelephone helmet, a headset, a concealed headset, an earphone alongside a separate microphone, an ear speaker in terms of a hearing device, and a microphone/earphone arrangement in a conference setting, whereupon the mechanism is integrated into or separate from the speaking/listening unit. 
         [0065]    The invention can also be embodied by a computer program, including program commands that cause a computer to execute the steps of the described procedure when the computer program is loaded on the computer or executed by it. The procedure according to the invention can also be embodied by a software product that is stored on a medium that can be read by a computer, and that preferably can be loaded directly into the internal memory of a computer, and includes the program code to perform the steps of the described procedure when the computer program is executed on the computer. Furthermore, the invention can be embodied by a digital storage medium with electrically readable control signals that can work with a programmable computer to manage communication processes, whereupon the control signals are configured and modified to prompt the computer to execute the steps of the described procedure. 
         [0066]    Other characteristics, functions, advantages, and details of this invention will be made even clearer in the description below with concrete exemplary embodiments and their graphical representation in the included figures. It is recognized that characteristics, features, advantages, and details of individual exemplary embodiments are transferable, and should also be considered disclosed in relation to the other exemplary embodiments, as long as they are not clearly groundless for technical or physical reasons. Exemplary embodiments can be combined with one another, and the combination can also be considered an exemplary embodiment of the invention. 
         [0067]    In the following, the invention is described in more detail using preferred exemplary embodiments and with the help of the accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0068]      FIG. 1  is a block diagram to illustrate the signal flows and signal processing steps according to a first exemplary embodiment of this invention. 
           [0069]      FIG. 2  is a block diagram to illustrate the signal flows and signal processing steps according to a second exemplary embodiment of this invention. 
           [0070]      FIG. 3  is a schematic diagram of a headset according to a third exemplary embodiment of this invention. 
           [0071]      FIG. 4  is a schematic diagram of a radio headset according to a fourth exemplary embodiment of this invention. 
           [0072]      FIG. 5  is a schematic diagram of a stereo headset according to a fifth exemplary embodiment of this invention. 
       
    
    
       [0073]    The figures are schematic and are not necessarily true to scale. The drawings and descriptions of them are only intended to be exemplary demonstrations of the principle of the invention, and they should not limit it in any way. 
       DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0074]    A first exemplary embodiment of this invention is illustrated in  FIG. 1  in the form of a block diagram of signal flows and signal processing steps. According to the diagram in  FIG. 1 , a signal processing block  100  has a transmitting end  102  and a receiving end  104 . On the transmitting end  102 , a voice signal S M  generated by a voice microphone  10  is fed to a microphone input  110 , and an ambient signal S N  generated by an ambient microphone  12  is fed to a microphone input  112 , while a transmission signal S out  is available at a transmission signal output  114 . On the receiving end  104 , a received signal S in  is received via a received signal input  116 , and a listening signal S H  is available at a speaker output  118 , which is fed to a speaker  18 . The microphone input  110  can also be considered a voice microphone input  110  or a voice signal input  110 ; the microphone input  112  can also be considered an ambient microphone input  110  or an ambient signal input  110 ; and the speaker output  118  can also be considered a listening signal output  118 . The ambient signal S N  can also be considered a noise signal in relation to the voice signal S M . 
         [0075]    On the transmitting end  102 , the voice signal S M  received at the microphone input  110  is passed through a branching point  126  described further below, and afterwards is fed to an input a of an adder  120 . Along with the input a, the adder  120  also has a negative (inverted) input b. This means the signal present at the negative input b is inverted before an addition, i.e., the phase is shifted by 180°. An adder with a negative input can also be considered a subtractor. The negative input b of the adder  120  is connected to an output of an attenuator  122 . 
         [0076]    The attenuator  122  receives the ambient signal S N  received at the microphone input  112  as an input signal. The attenuator  122  subjects the ambient signal S N  to an attenuation function G(f). G(f) is a frequency-dependent attenuation function G(f)=A x *E(f), where E(f) represents a (listening-/voice-/audio-)frequency-dependent equalization function (equalizer, frequency-response distortion) that can also be programmable, and A x  represents an attenuation that is constant with regard to the frequency and configurable by at least one variable “x.” G(f) is a combination of frequency response predistortion and a constant attenuation, and there can also be a frequency range with amplification as negative attenuation overall. The attenuation function G(f) can be used on the input signal, e.g., the ambient signal S N , to improve intelligibility of speech and balance the room conditions. The characteristics of the attenuation function G(f) can be influenced by the control signal S c1  that can be fed in from the outside. This makes an attenuated ambient signal S N ×G(f) available at the output of the attenuator  122 . 
         [0077]    The attenuated ambient signal is passed through a branching point  128  described further below, and afterwards is fed to a negative input b of the adder  120 . After the addition of the inputs a, b in the adder  120 , an environment-compensated voice signal S M −S N ×G(f) is present at its output x, which is then subjected to another Automatic Gain Control (AGC)  124 , and fed to the transmission signal output  114  as the transmission signal S out  after being passed through a branching point  130  described further below. According to the above description, the transmission signal S out  can be expressed with the following formula: 
         [0000]        S   out   =AGC ( S   M   −S   N   ×G ( f )) 
         [0078]    The transmission signal output  114  is also an interface with a communication network (not shown in detail here) to transmit the transmission signal S out . 
         [0079]    On the receiving end  104 , the received signal S in  received from the communication network via the received signal input  116  is processed in three adders  140 ,  144 , and  148 , and then fed to the speaker output  118  as the listening signal S H  as described in more detail below. The received signal S in , after being processed in the three adders  140 ,  144 , and  148 , is fed to the equalizer E(f), whereupon the output of the equalizer is fed to the speaker output  118 . The equalizer can be designed to be ear-specific, whereupon a custom user hearing impairment, e.g., a hearing impairment of a person wearing a hearing aid, or another type of hearing impairment (loss of hearing sensitivity in higher frequency ranges, e.g., due to age, after an accident, etc., chronic hearing damage from listening to music too loudly as a child) can be balanced with this equalizer to improve the intelligibility of speech. To balance a user-specific hearing impairment, the equalizer function E(f) can be defined by measuring the hearing spectrum of the user, called “calibrating” in short. The calibration can be conducted as with adjusting a hearing aid. Alternately, preset frequency responses/frequency-response curves are conceivable, where the user could select at least one. 
         [0080]    First, the received signal S in  received at the received signal input  116  is fed to a first input a of the adder  140 . The adder  140  has two positive inputs a, b. The second input b of the adder  140  is connected to an output signal of an attenuator  142 . 
         [0081]    The attenuator  142  receives the microphone signal S M  tapped (branched) at the branching point  126  on the transmitting end  102 , and subjects it to an attenuation factor R 1  that can be influenced by a control signal S c2  that can be fed in from the outside. In other words, an attenuated voice signal S M ×R 1  is present at the output of the attenuator  142 . 
         [0082]    The attenuated voice signal is fed to the second input b of the adder  140 , and added to the received signal S in  present at the first input a. There is then an addition signal S in +S M ×R 1  present at the output x of the adder  140 . 
         [0083]    The addition signal is fed to the first input a of the next adder  144 . The second input b of the adder  144  is a negative input that is connected to an output of an echo compensator (EC)  146 . 
         [0084]    The echo compensator  146  receives the transmission signal S out  tapped (branched) at the branching point  130  on the transmitting end  102 , and processes it so that an echo compensation signal S EC  output as the result corresponds to an anticipated echo of the transmission signal S out  in the received signal S in . To do this the echo compensator  146  subjects the tapped transmission signal S out  to a preset delay and attenuation, as is already known by itself in the art. 
         [0085]    The echo compensation signal S EC  output from the echo compensator  146  is fed to the negative input b of the adder  144 , and subtracted from the addition signal present at the positive input a. Accordingly, there is an echo-compensated addition signal S in +S M ×R 1 −EC(S out ) present at the output x of the adder  144 . 
         [0086]    The echo-compensated addition signal is fed to the input a of the last adder  148 . The second input b of the adder  148  is again a negative input that is connected to an output of another attenuator  150 . 
         [0087]    The attenuator  150  receives the attenuated ambient signal S N ×G(f) tapped at the branching point  128  on the transmitting end  102 , and subjects it to an attenuation factor R 2 . The attenuation factor R 2  can be influenced by a control signal S c3  that can be fed in from the outside. The now twice attenuated ambient signal S N ×G(f)×R 2  is fed to the negative input b of the adder  148 , and subtracted from the echo-compensated addition signal present at the positive input a. Therefore, a signal is present at the output x of the adder  148  that can then optionally be fed to an equalizer E ind (f) that is customized to the hearing of the user/headset wearer to balance out any hearing impairment on the part of the user. The output of the optional equalizer or the output  148  is then fed as the listening signal S H  to the speaker output  118 . According to the above description, the listening signal S H  can be expressed with the following formula: 
         [0000]    
       
         
           
             
               
                 
                   
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         [0088]    whereupon without balancing out the user&#39;s hearing impairment, the equalizer function E ind (f) is set to 1. 
         [0089]      FIG. 2  shows a second exemplary embodiment of this invention in the form of a schematic block diagram to illustrate the signal flows and signal processing steps. This exemplary embodiment can be considered a variation of the first exemplary embodiment, which is why components of the second exemplary embodiment that have already been described in the first exemplary embodiment are assigned the same reference numbers, and are described in less detail unless a more detailed description is helpful to aid comprehension. With regard to the same elements, reference can also be made to the explanations in the first exemplary embodiment. 
         [0090]    According to the diagram in  FIG. 2 , a signal processing block  200  has a transmitting end  202  and a receiving end  204 . As in the first exemplary embodiment, on the transmitting end  102 , a voice signal S M  is received from a voice microphone  10  via a microphone input  110  and an ambient signal S N  is received from an ambient microphone  12  via a microphone input  112 , and a transmission signal S out  is output via a transmission signal output  114 . To differentiate between other ambient microphones and ambient signals that will be described below, the ambient signal S N  will hereinafter be considered the general ambient signal S N , and the ambient microphone  12  will be considered the general or global ambient microphone  12 . As in the first exemplary embodiment, the general ambient signal S N  is subjected to an attenuation function G(f) by the attenuator  112  with characteristics that can be influenced by a control signal S c1 , and then fed to the negative input b of the adder  120  to be subtracted from the voice signal S M  there, and the output of the adder  120  will be output—after applying the automatic gain control  124 —as the transmission signal S out  at the transmission signal output  114  to a communication network not shown in detail here. 
         [0091]    On the receiving end  204 , a received signal S M  is received from the communication network via the received signal input  216 , whereupon the received signal S in , in contrast to the first exemplary embodiment, is a stereo received signal, including a left and right channel, and the received signal input  216  is therefore also designed as a stereo input. 
         [0092]    The stereo received signal S in  is first fed to an adder  240 , which differs from the adder  140  in the first exemplary embodiment in that it has a stereo input ab, an addition input c, and a stereo output xy. The addition takes place in a way that the signal present at the addition input c is added to both channels of the stereo signal present at the stereo input ab. As described, the received signal S in  received via the received signal input  216  on the receiving end  204  is present at the stereo input ab. As in the first exemplary embodiment, the attenuated voice signal, attenuated through the attenuator  142  by the attenuation factor R 1  that can be influenced by the control signal S c2 , is present at the addition input c of the adder  240 . Thus, an output signal S in +S m ×R 1  is present at the output xy of the adder  240 , which is fed to a stereo input ab of another adder  244 . 
         [0093]    The adder  244  differs from the adder  144  from the first exemplary embodiment only in its stereo design. Thus, along with its stereo input ab, it also has a negative input c and a stereo output xy. As in the first exemplary embodiment, the echo compensation signal S EC =EC(S out ) generated by the echo compensator  146  is fed to the negative input c of the adder  244 . In contrast with the first exemplary embodiment, in this exemplary embodiment, the characteristics of the echo compensator  146  can also be influenced by another control signal S c4 . Thus, there is an echo-compensated addition signal S m +S M ×R 1 −EC(S out ) at the output xy of the adder  244 , which is fed to a stereo input ab of a splitter  252 . 
         [0094]    The splitter  252  separates the stereo received signal present at the input ab into separate mono outputs l and r, which are then processed in separate signal paths. There is a processing path emanating from output l for a left listening channel, and a processing path emanating from output r for a right listening channel. 
         [0095]    In addition, along with the speaker output  118  that has a left listening signal S H,l  for the speaker  18 , which is considered the left speaker  18  here, the receiving end  204  of the signal processing block  200  in this exemplary embodiment also has another speaker output  229 , where a right listening signal S H,r  is present for a right speaker  29 . A left ear sound microphone  21 , and a right ear sound microphone  23  are also included. A signal generated by the left ear sound microphone  21  is received in the signal processing block at the left microphone input  221  as a left ear signal S N,l , and fed to an attenuator  254 . The attenuator  254  provides an attenuation function G l (f). The characteristics of the attenuation function G l (f) can be influenced by a control signal S c5 . Likewise, a signal generated by the right ear sound microphone  23  is received at a right microphone input  223  as the right ear signal S N,r , and fed to an attenuator  255 , where it is subjected to an attenuation function G r (f), with characteristics that can be influenced by another control signal S c6 . The left and right ear signal S N,l , S N,r  can—to differentiate from the general ambient signal S N —also be considered the left and right specific ambient signal S N,l , S N,r . The microphone input  112  can also be considered the general ambient microphone input  110  or the general ambient signal input  110 ; the left and right microphone input  221 ,  223  can also be considered the left/right ear signal input  221 ,  223 , the left/right specific microphone input  221 ,  223 , the left/right specific ambient signal input  221 . 
         [0096]    If the received signal S in  is considered a combined signal with the parts S in,l , S in,r  for the left and right channel, according to the description above, a left echo-compensated addition signal S in,l +S M ×R 1 −EC(S out ) is present at the left output l of the splitter  252 , and a right echo-compensated addition signal S in,r +S M ×R 1 −EC (S out ) is present at the right output r of the splitter  252 . The left echo-compensated addition signal is then fed to the first input of the adder  148 , which corresponds to the adder  148  of the first exemplary embodiment. Likewise, the right echo-compensated addition signal is fed to a first input a of another adder  249 , which matches the adder  148  in design. 
         [0097]    On the left side, the left ear signal S N,1 ×G 1 (f) attenuated by the attenuator  254  is now fed to the negative input of the adder  148 , and as described in the first exemplary embodiment, the output signal of the adder  148  will optionally be fed to a custom equalizer for the left ear E ind,l (f) which balances out any hearing impairment of the left ear. The output of the optional equalizer or the output  148  will then be fed to the speaker output  118  as the (here: left) listening signal S H,l . Similarly, on the right side, the right ear signal S N,r ×G r (f) attenuated by the attenuator  255  is fed to a negative input b of the adder  249 , and a signal present at an output x of the adder  249  is optionally fed to a custom equalizer for the right ear or E ind,r  (f) which balances out any hearing impairment of the right ear. The output of the optional equalizer or the output  249  is then fed as the right listening signal S H,r  to the microphone output  229 . 
         [0098]    As can be seen in the above description, the left listening signal S H,l  can be expressed with the following formula: 
         [0000]    
       
         
           
             
               
                 
                   
                     S 
                     
                       H 
                       , 
                       1 
                     
                   
                   = 
                     
                    
                   
                     
                       
                         E 
                         
                           ind 
                           , 
                           1 
                         
                       
                        
                       
                         ( 
                         f 
                         ) 
                       
                     
                     × 
                     
                       ( 
                       
                         
                           S 
                           
                             in 
                             , 
                             1 
                           
                         
                         + 
                         
                           
                             S 
                             M 
                           
                           × 
                           
                             R 
                             1 
                           
                         
                         - 
                         
                           EC 
                            
                           
                             ( 
                             
                               S 
                               out 
                             
                             ) 
                           
                         
                         - 
                         
                           
                             S 
                             
                               N 
                               , 
                               1 
                             
                           
                           × 
                           
                             
                               G 
                               1 
                             
                              
                             
                               ( 
                               f 
                               ) 
                             
                           
                         
                       
                       ) 
                     
                   
                 
               
             
             
               
                 
                   = 
                     
                    
                   
                     
                       
                         E 
                         
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                           , 
                           1 
                         
                       
                        
                       
                         ( 
                         f 
                         ) 
                       
                     
                     × 
                     
                       ( 
                       
                         
                           S 
                           
                             in 
                             , 
                             1 
                           
                         
                         + 
                         
                           
                             S 
                             M 
                           
                           × 
                           
                             R 
                             1 
                           
                         
                         - 
                         
                           EC 
                            
                           
                             ( 
                             
                               AGC 
                                
                               
                                 ( 
                                 
                                   
                                     S 
                                     M 
                                   
                                   - 
                                   
                                     
                                       S 
                                       N 
                                     
                                     × 
                                     
                                       G 
                                        
                                       
                                         ( 
                                         f 
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                                 ) 
                               
                             
                             ) 
                           
                         
                       
                       ) 
                     
                   
                 
               
             
           
         
       
     
         [0099]    and the right listening signal S H,r  can be expressed with the following formula: 
         [0000]    
       
         
           
             
               
                 
                   
                     S 
                     
                       H 
                       , 
                       r 
                     
                   
                   = 
                     
                    
                   
                     
                       
                         E 
                         
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                           , 
                           r 
                         
                       
                        
                       
                         ( 
                         f 
                         ) 
                       
                     
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                       ( 
                       
                         
                           S 
                           
                             in 
                             , 
                             r 
                           
                         
                         + 
                         
                           
                             S 
                             M 
                           
                           × 
                           
                             R 
                             1 
                           
                         
                         - 
                         
                           EC 
                            
                           
                             ( 
                             
                               S 
                               out 
                             
                             ) 
                           
                         
                         - 
                         
                           
                             S 
                             
                               N 
                               , 
                               r 
                             
                           
                           × 
                           
                             
                               G 
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                              
                             
                               ( 
                               f 
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                       ) 
                     
                   
                 
               
             
             
               
                 
                   = 
                     
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                           , 
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                         ( 
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                             S 
                             M 
                           
                           × 
                           
                             R 
                             1 
                           
                         
                         - 
                         
                           EC 
                            
                           
                             ( 
                             
                               AGC 
                                
                               
                                 ( 
                                 
                                   
                                     S 
                                     M 
                                   
                                   - 
                                   
                                     
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                                       N 
                                     
                                     × 
                                     
                                       G 
                                        
                                       
                                         ( 
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                             ) 
                           
                         
                       
                       ) 
                     
                   
                 
               
             
           
         
       
     
         [0100]    whereupon without balancing out the hearing impairment of the left and/or right ear, the functions E ind,l (f) and/or E ind,r (f) are set to 1. Balancing out the hearing impairment of the left and/or right ear provides for improved localization of a noise, like a car, for example, which improves the comprehensibility of speech. 
         [0101]    As indicated by the dash-dotted lines in  FIG. 2 , the voice microphone  10  and the general ambient microphone  12  are structurally combined in this embodiment. This can be, but is not limited to being, in the form of a double microphone with opposite directional characteristics. In addition, the speaker  18  and the left ear sound microphone  21  are structurally combined, and the right speaker  29  and the right ear sound microphone  23  are structurally combined. This type of structural unity can be, but is not limited to being, integrated in a headphone cup on the corresponding side or in an earpiece in the form of an earplug or an earmold, whereupon an emission direction for the speaker  18 ,  29  is each directed at one ear of the wearer, and a directional characteristic of the ear sound microphone  21 ,  23  is directed away from the wearer&#39;s ear. 
         [0102]    In the first as well as the second exemplary embodiment, each of the elements shown in the signal processing block  100 ,  200  can be interpreted as components (circuitry, wiring, solder points, etc.) of a physically realized circuit arrangement or as a processing step of a signal processing procedure. 
         [0103]      FIG. 3  shows a third exemplary embodiment of this invention, where the signal processing block  100  of the first exemplary embodiment is used with a headset  330  within the scope of a conference system. 
         [0104]    In detail, according to the diagram in  FIG. 3 , a headset  330  includes an earpiece  332 , a headband  334 , and a pressure piece  335 , where the speaker  18  (see also  FIG. 1 ) is located in the earpiece  332 . Out of the earpiece  332  protrudes a microphone arm  336  with a microphone mount  337  at its end where the voice microphone  10  (see also  FIG. 1 ) is located. The microphone mount  337  is surrounded by a windscreen or pop filter  338 . A speaker wire  318  connected to the speaker  18 , and a microphone wire  310  connected to the voice microphone  10  extend through a strain relief  339  attached to the outside of the earpiece  332 , and continue as wires of a headphone cable  340 . The headset  330  is designed so the earpiece  332  rests against one ear of the wearer of the headset  330 , while the pressure piece  335  rests above the opposite ear of the wearer against the head, and the earpiece  332  and the pressure piece are pressed against the head of the wearer from the pressure of the headband  334 , holding the headset  330  to the head of the wearer. The earpiece  332  can be of open or closed design. The microphone arm  336  stretches along the cheek of the wearer of the headset  330  to the mouth so the voice microphone  10  is located in the vicinity of the speaker&#39;s mouth to clearly capture the speech of the wearer of the headset  330 . The pop filter  338  insulates against disruptive wind noise or heavily aspirated utterances that are often overemphasized by a microphone, and it can be made of a foam material, for example. The pop filter  338  is removable and can be replaced for hygienic reasons if the headset  330  is used by multiple wearers. 
         [0105]    A microphone housing  350  is located in the vicinity of the headset  330 , either on a wall or on a desk or the like, for example. The microphone housing  350  houses the ambient microphone  12  (see also  FIG. 1 ) and is arranged to record ambient noise that can also reach the voice microphone  10  of the headset  330 , while not recording the voice sound of the wearer of the headset  330  or only recording it at a much lower level than through the voice microphone  10 . An ambient signal wire  312  is connected to the ambient microphone  12 , which stretches through a strain relief  352  on the microphone housing  350 , and continues through a microphone cable  360 . 
         [0106]    The speaker wire  318 , the microphone wire  310 , and the ambient signal wire  312  all terminate in a switch box  370 . More precisely, the microphone cable with the ambient signal wire  354  is connected to a cable connector  372  of the switch box  370 , and the headphone cable with the microphone wire (also considered the voice wire)  310  and the speaker wire  318  is connected to a cable connector  374  of the switch box  370 . In addition, a conference connection cable  380  with a transmitting wire and a receiving wire (neither shown in detail here) is connected to a cable connector  376  of the switch box  370 . 
         [0107]    As shown in  FIG. 3 , the switch box  370  accepts the signal processing block  100  of the first exemplary embodiment (see  FIG. 1 ), which can also be considered a signal processing circuit  100 . Here, the microphone input  112  of the processing block  100  is connected to the cable connector  372  of the switch box  370 , the microphone input  110  and the speaker output  118  of the processing block  100  are connected to the cable connector  374  of the switch box  370 , and the transmission signal output  114  and the received signal input  116  are connected to the cable connector  376  of the switch box  370 . Consequently, a voice signal S M , generated in the voice microphone  10 , can be transmitted to the switch box  370  via the microphone wire  310 , a listening signal S H  can be transmitted from the switch box  370  to the speaker  18  via the speaker wire  318 , an ambient signal S N , generated in the ambient microphone  12 , can be transmitted to the switch box  370  via the ambient signal wire  354 , and a transmission signal S out  can be transmitted from the switch box  370  to an external location (not shown in detail here) and a received signal S in  can be transmitted from the external location to the switch box  370  via the conference connection cable  380 . 
         [0108]    In addition, the switch box  370  has three control dials  378  that generate control signals S c1 , S c2 , and S c3  upon being rotated or based on their position. The control signals S c1 , S c2 , and S c3  are routed to the signal processing block  100  via terminals that are not shown in detail here. 
         [0109]    The signal processing block  100  with its inputs and outputs  110 ,  112 ,  114 ,  116 , and  118 , the voice microphone  10 , the ambient microphone  12 , the speaker  18 , and the signals S M , S H , S N , S in , S out , S c1  through S c3  fully correspond in meaning, design, and effect to the diagrams and descriptions with relation to the first exemplary embodiment as per  FIG. 1 , such that their descriptions there can be referenced in their entirety. 
         [0110]    As can be seen in  FIG. 1 , the signal processing block  100  generates the transmission signal S out  according to the following formula: 
         [0000]        S   out   =AGC ( S   M   −S   N   ×G ( f )) 
         [0111]    and the listening signal S H  according to the following formula: 
         [0000]        S   H   =S   in   +S   M   ×R   1   −S   N   ×R   2   ×G ( f )− EC ( S   out )).
 
         [0112]    In other words, the voice signal S M  recorded via the voice microphone  10  is processed into the transmission signal S out  by subtracting the ambient signal S N  generated by the ambient microphone  12  and attenuated with a suitable attenuation function G(f) from the voice signal S M , and lastly subjecting the result to an Automatic Gain Control (AGC). On the other end, the received signal S in  is processed into the listening signal S H  by adding the voice signal S M , corrected with a suitable attenuation or amplification factor R 1 , to the received signal S in , and removing the ambient signal S N  with suitable attenuation, whereupon echo compensation is also designed in such a way that the transmission signal S out  on this end is subtracted from the received signal S in  after the appropriate delay and attenuation, in order to suppress any echo effects of the transmission signal S out  from this end in the received signal S in . 
         [0113]    This provides the user or wearer of the headset  330  with an acceptable auditory impression of his or her own voice, even in a loud environment. In the process, the ambient noise and his or her own voice can be attenuated differently (the voice can also be amplified) based on the situation, so the ambient noise does not have to be completely muted for the wearer. Otherwise, the wearer can use the control dial to attenuate the ambient noise to the extent that it essentially doesn&#39;t distract from the conversation. 
         [0114]    The headset  330  according to this exemplary embodiment can be used for a variety of applications, like according to the description above for teleconferencing or in a conference system with a variety of participants. However, the application is not limited to this; rather, it also includes applications on a headset for cellular phones or a radio, for the workstation of a simultaneous interpreter, a sport commentator in a stadium or another sports venue, a journalist or correspondent in a loud environment or comparable situations, a speaker/translator booth, a broadcast vehicle, a switchboard, etc. 
         [0115]    The earpiece  332  can be noise isolating, and an earmuff can be included at the pressure piece  335  or in place of it. In this case, the described arrangement is also suitable for use in a very loud environment like a helicopter or aircraft cockpit, construction equipment or the like, in loud industrial environments, in nightclubs, etc. 
         [0116]    In a variation, a speaker can be included at the second ear, so a single-channel received signal S in  can be heard the same in both ears, or a stereo received signal S in  can be divided among the two ears/speakers after being processed as described. 
         [0117]    In place of cable connections  340 ,  360 ,  380 , wireless connections like Bluetooth, infrared, ultrasound, or other wireless standards can be used. 
         [0118]    The switch box  370  can include an arrangement of multiple signal processing blocks  100  to process signals from a variety of conference participants. Here, the received and transmission signal terminals  114 ,  116  can be connected to a conference control module that can be considered a communication network. 
         [0119]    As a fourth exemplary embodiment of this invention,  FIG. 4  shows a radio headset  400  with a compact or concealed design that can be used with a cell phone, a radio, or hands-free equipment that is not shown in detail here. This radio headset has the signal processing block  100  and all of the other elements of the first exemplary embodiment according to  FIG. 1  built-in. 
         [0120]    The headset  400  has an earpiece  430  with a housing  432  and an ear adapter  434 , whereupon the housing  432  holds the speaker  18 , and whereupon the ear adapter  434  is designed to insert into the ear canal of the ear of the person wearing the headset  400 . An air duct  436  stretches from the speaker  18  in the housing  432  through the ear adapter  434  so the sound waves emitted by the speaker  18  can be transmitted unobstructed to the ear canal of the wearer. 
         [0121]    A microphone arm  450  can swivel via a hinge  440  connected to the housing  432  of the earpiece  430 . The microphone arm  450  has a microphone mount  452  and an arm  454  that connects the microphone mount  452  to the hinge  440 . The microphone mount  452  holds the voice microphone  10  and the ambient microphone  12 . The wall of the microphone mount  452   s  features perforations or cut-outs  452   a ,  452   b  that make it easier for sound to get to the voice microphone  10  or the ambient microphone  12 . The voice microphone  10  and the ambient microphone  12  are designed as a double-microphone unit with opposite directional characteristics (i.e., opposite sound acceptance directions). The perforations  452   a ,  452   b  are positioned at least approximately along a continuation of the sound acceptance directions of the microphones  10 ,  12 , and they aid their directivity. The sound acceptance direction of the voice microphone  10  and the associated perforations  452   a  are facing the anticipated mouth position of the wearer of the headset  400 , while the sound acceptance direction of the ambient microphone  12  and the associated perforations  452   b  are facing the opposite direction. This arrangement also ensures that the voice microphone  10  favorably captures the voice sound of a wearer of the headset  400  (including ambient noise, naturally), while the ambient microphone  12  captures the ambient sound, but the voice sound of the wearer is specifically faded out or shielded from this microphone. 
         [0122]    The headset also has a rear earpiece  460  and a connecting piece  470 . The connecting piece  470  connects the rear earpiece  460  with the earpiece  430 . The connecting piece  470  and the rear earpiece  460  are designed so the rear earpiece  460  can be worn comfortably behind the ear of the wearer, while the connecting piece  470  stretches above the ear or rests against a top edge of the ear when the earpiece  430  is placed in the wearer&#39;s ear. Incidentally, without limiting their universality, the earpiece  430 , the connecting piece  470  and the rear earpiece  460  are design to be one piece. 
         [0123]    The rear earpiece  460  includes a switch module  480 , which has an antenna block  482 , a control signal block  484 , and the signal processing block  100 . The antenna block  482  is designed and equipped to send and receive signals via a radio interface with a receiver like a cell phone or other device mentioned above. A radio connection from the antenna block  482  to a receiver is represented by a dashed line and labeled KOM. 
         [0124]    The signal processing block  100  is shown in detail in  FIG. 1 , and its design, function, and operation have already been described in relation to the first exemplary embodiment. The microphone input  110  of the signal processing block  100  is connected to the voice microphone  10  via a voice signal wire  410  so a voice signal S M  generated by the voice microphone  10  is present at the microphone input  110  of the signal processing block  100 . The microphone input  112  of the signal processing block  100  is connected to the ambient microphone  12  via an ambient signal wire  412  so an ambient signal S N  generated by the ambient microphone  12  is present at the microphone input  112  of the signal processing block  100 . The listening signal output  118  of the signal processing block is connected to the speaker  18  via a listening signal wire  418  so a listening signal S H  output via the speaker output  118  of the signal processing block  100  is transmitted to the speaker  18 . The received signal input  116  and the transmission signal output  114  of the signal processing block  100  are connected to the antenna block  482  of the switch module  480  so received and transmission signals S in , S out  can be exchanged between the signal processing block  100  and the antenna block  482 . 
         [0125]    As shown in  FIG. 4 , a button panel  490  with multiple buttons is included on the top of the connecting piece  470 . The buttons on the button panel  490  are available to the wearer to operate the headset  400  without having to take the headset  400  off. Pressing the buttons on the button panel  490  allows the wearer to send control signals S c  to the switch module  480 . The control signals S c  include both control signals S c1  through S c3  to influence the characteristics of the attenuators  122 ,  142 ,  150  (see  FIG. 1 ) of the signal processing block  100 , and control signals to initiate or terminate radio communication via the antenna block  482  and to increase or decrease the overall signal strength of the listening signal S H , whereupon certain control signals can also be sent via the antenna block  482  to the receiver, like a cell phone, etc. to conveniently trigger control processes there. 
         [0126]    Processing the voice signal S M  to the transmission signal S out  and processing the received signal S in  to the listening signal S H  correspond to the processing procedures described in relation to the first and the third exemplary embodiments, such that these can be referenced from this point in this respect. 
         [0127]    As a fifth exemplary embodiment of this invention,  FIG. 5  shows a stereo headset  500  that can be used with a cell phone, a radio, or hands-free equipment that is not shown in detail here. This headset has the signal processing block  200  and all of the other elements of the second exemplary embodiment according to  FIG. 2  built-in. 
         [0128]    The stereo headset  500  includes a left listening unit  530 , a right listening unit  540 , and a voice unit  550 . The voice unit  550  includes a housing  552 , which holds the control board  560 . The control board  560  bears the signal processing block  200 . Microphones  10 ,  12 ,  21 ,  23  and speakers  18 ,  23  (see also  FIG. 2 ) are distributed among the voice unit  550  and the listening units  530 ,  540  as described below. 
         [0129]    The left listening unit  530  includes an earpiece  532  that can be inserted into the (left, according to the design) ear canal of the ear of the person wearing the stereo headset  500 , and a grip  534  integrated into the earpiece  532  by design, which can be grabbed from the outside when the earpiece  532  is inserted in the ear canal. The left listening unit  530  houses the (left) speaker  18  and the left ear sound microphone  21 . A left earpiece cable  536  stretches between a grommet-like extension of the grip  534  on the left listening unit  530  and a strain relief  554  on the voice unit  550 . The left earpiece cable  536  includes a speaker wire that connects the left speaker  18  with the speaker terminal  118  on the signal processing block  200 , and a microphone wire that connects the left ear sound microphone  21  with the microphone terminal  221  on the signal processing block  200 , so a left ear signal S N,l  generated by the left ear sound microphone  21  can be fed to the microphone input  221  of the signal processing block  200 , and a left listening signal S H,l  generated by the signal processing block  200  can be fed from the left speaker output  118  to the left speaker  18 . 
         [0130]    Likewise, the right listening unit  540  includes an earpiece  542  and a grip  554 , and the right speaker  29  and the right ear sound microphone  23  are housed in the right listening unit  540 . A right earpiece cable  546  stretches between a grommet-like extension of the grip  544  on the right listening unit  540  and a strain relief  554  on the voice unit  550 . The right earpiece cable  546  includes a speaker wire that connects the right speaker  29  with the speaker terminal  229  on the signal processing block  200 , and a microphone wire that connects the right ear sound microphone  23  with the microphone terminal  223  on the signal processing block  200 , so a right ear signal S N,r  generated by the right ear sound microphone  23  can be fed to the microphone input  223  of the signal processing block  200 , and a right listening signal S H,r  generated by the signal processing block  200  can be fed from the right speaker output  229  to the right speaker  29 . The left earpiece cable  536  and the right earpiece cable  546  are collected together in a bundling ring that surrounds the cables  536 ,  546  tightly, but still allows movement. 
         [0131]    On the control board  560  inside the voice unit  550 , the voice microphone  10  and the ambient microphone  12  are fastened such that the voice microphone  10  is located near housing cut-outs or perforations  552   a  at the top end of the housing  552  and the general ambient microphone  12  is located near housing cut-outs or perforations  552   b  at the bottom end of the housing  552 . These microphones  10 ,  12  are arranged such that their sound acceptance directions point toward the respective perforations  552   a ,  552   b . This arrangement also ensures that the voice microphone  10  favorably captures the voice sound of a wearer of the headset  500  (including ambient noise, naturally), while the ambient microphone  12  captures the ambient sound, but the voice sound of the wearer is specifically faded out. The voice microphone  10  is connected directly to the microphone input  110  of the signal processing block  200  via a wire, and the ambient microphone  12  is connected directly to the microphone input  112  of the signal processing block  200  via a wire so a voice signal S M  generated by the voice microphone  10  is fed to the microphone input  110 , and the general ambient signal S N  is fed to the microphone input  112 . 
         [0132]    A connection cable  570  is fed into the voice unit  550  via a strain relief  555  on the voice unit  550 . The connection cable  570  has a single-wire output line connected to the transmission signal terminal  112  of the signal processing block  200 , and a two-wire received signal line connected to the stereo received signal terminal  216  of the signal processing block  200 . The connection cable  570  ends in a plug  572  that, without limiting its universality, is a four-pin jack. A four-pin jack is very common for use with stereo headsets, and it can be wired with a left input signal at the tip, a right input signal at the contact ring directly next to the tip, an output signal at the second or third contact ring, and a ground at the remaining contact ring. This allows the connection cable  570  to exchange the two-channel received signal S in  and the transmission signal S out  with a receiver (not shown in detail here), according to the description in the second exemplary embodiment. 
         [0133]    As shown in  FIG. 5 , the voice unit  550  has two buttons  556 ,  557  and an adjustment wheel  558 , which are all accessible on the side of the housing  552 . The buttons  556 ,  557  and the adjustment wheel  558  are designed to be used by the wearer of the headset  500 . Actuations or adjustment positions of the buttons  556 ,  557  and the adjustment wheel  558  are interpreted by a control signal block (not shown in detail here) that is mounted on the control board  560 , and converted into control signals S c  that can be fed to the signal processing block  200 . The control signals S c  include the control signals S c1  through S c6  to influence the characteristics of the attenuators  122 ,  142 ,  254 ,  255  (see  FIG. 2 ) and the echo compensator  146  of the signal processing block  200  according to the description in the second exemplary embodiment. In addition, control signals can also be generated for a connection control block (not shown in detail here) to initiate or terminate radio communication and control signals for an amplifier block (not shown in detail here) to increase or decrease the overall signal strength of the listening signal S H,l , S H,r , and/or control signals that can be sent via the connection cable  570  to the receiver, like a cell phone, etc., to conveniently trigger control processes there. 
         [0134]    Design and functionality of the signal processing block  200 , the microphones  10 ,  12 ,  21 ,  23  and the speakers  18 ,  29 , as well as the effects that they can achieve were shown in  FIG. 2 , and described in detail in the context of the second exemplary embodiment. The depiction and description of these in the second exemplary embodiment as per  FIG. 2  can be referenced in their entirety. In particular, the voice signal S M  is processed to convert it into the transmission signal S out , whereupon the processing can be expressed with the following formula: 
         [0000]        S   out   =AGC ( S   M   −S   N   ×G ( f )) 
         [0135]    and the received signal S in  is processed to convert it into the left and right listening signal S H,l  and S H,r , whereupon the processing can be expressed by the following formulas: 
         [0000]        S   H,l   =S   M   ×R   1   −EC ( S   out )− S   N,l   ×G   1 ( f )
 
         [0000]      and 
         [0000]        S   H,r   =S   in,r   +S   M   ×R   1   −EC ( S   out )− S   N,r   ×G   r ( f )
 
         [0136]    This invention was described and illustrated in drawings above using preferred exemplary embodiments. However, it must be noted that this invention is solely defined by the independent patent claims, and the above exemplary embodiments, variations, and refinements are only provided as exemplary illustrations. Not all of the elements described above are completely necessary for the application and execution of this invention to the extent that they are not covered in at least one independent claim as a mandatory feature. In place of variability, one or all of the attenuators and the echo compensators can have fixed preset characteristics. The signal inputs can be assigned to input amplifiers, and the listening signal outputs can be assigned to output amplifiers. 
         [0137]    For the purposes of this invention, the signal processing blocks  100 ,  200  each correspond to a procedure or a mechanism for controlling voice communication of a first person with at least a second person via a communication network; the transmitting end  102 ,  202  each corresponds to a step of the procedure of generating a transmission signal by processing a voice signal; the transmitting end  104 ,  204  each corresponds to a step of the procedure of generating a listening signal by processing the received signal; the ambient signal S N  corresponds to a general ambient signal; the left and right ear signal S N,l  and S N,r  correspond to a specific ambient signal; the voice microphone  10  corresponds to a first microphone; the microphone input  110  corresponds to a step of the procedure to receive a voice signal; the transmission signal output  114  corresponds to a step of the procedure of transmitting the transmission signal to the communication network; the received signal input  116 ,  216  corresponds to a step of the process of receiving a received signal from the communication network; the speaker output  118 ,  229  corresponds to a step of the procedure of transmitting the listening signal to a speaker; the branching points  126 ,  128 ,  130  correspond to a step of the procedure of branching; the adders  120 ,  140 ,  144 ,  240 ,  244 ,  148 ,  249  correspond to a step of the procedure of adding signals (or subtracting signals if a signal input of the adder is negative); the attenuators  122 ,  142 ,  150 ,  254 ,  255  correspond to a step of the procedure of subjecting a signal to attenuation or amplification; the echo compensator  146  corresponds to a step of the procedure of subjecting a signal to echo compensation; the microphone input  112  corresponds to a step of the procedure of receiving a general ambient signal; The (general) ambient microphone  12  corresponds to a second microphone; the ear sound microphones  21 ,  23  correspond to a third microphone; the microphone inputs  221 ,  223  correspond to a step of the procedure of receiving a specific ambient signal; and the control signals represent a variability of attenuation, amplification, or delay properties. 
         [0138]    In additional variations of this invention not shown in the drawings, to compensate for the ambient signal in the listening signal, the ambient signal (general ambient signal) S N  in  FIG. 1  can be tapped before the attenuator  122 , the received signal in  FIG. 1  can also be a stereo received signal, and the described processing can affect both channels, the (mono) received signal in  FIG. 1  can be distributed among two speakers after the described processing, the received signal in  FIG. 2  can also be a mono received signal that can be processed into a single listening signal or a two-channel listening signal by the described procedure, and so forth. 
         [0139]    The characteristics of the invention described in reference to the illustrated embodiments can also be present in other embodiments of the invention, unless otherwise indicated or intrinsically prohibited for technical reasons. 
       LIST OF REFERENCE NUMBERS AND SYMBOLS 
       [0000]    
       
           10  Voice microphone 
           12  (General) ambient microphone 
           18  Speaker, single or left 
           21  Ear sound microphone (specific ambient microphone), left 
           23  Ear sound microphone (specific ambient microphone), right 
           29  Speaker, right 
           100 ,  200  Signal processing block 
           102 ,  202  Transmitting end 
           104 ,  204  Receiving end 
           110 ,  112 ,  221 ,  223  Microphone inputs 
           114  Transmission signal output 
           116 ,  216  Received signal input 
           118 ,  229  Speaker outputs 
           122  Attenuator G(f) 
           120 ,  144 ,  148 ,  249  Adder, subtracting 
           140 ,  240  Adder, adding 
           124  Automatic Gain Control (AGC) 
           146  Echo compensator 
           142  Attenuator R 1   
           150  Attenuator R 2   
           252  Splitter (SPLT) 
           254  Attenuator, left channel G l (f) 
           255  Attenuator, right channel G r (f) 
           310  Voice signal wire 
           312  Ambient signal wire 
           318  Listening signal wire 
           330  Headset 
           332  Earpiece 
           334  Headband 
           335  Pressure piece 
           336  Microphone arm 
           337  Microphone mount 
           338  Windscreen/pop filter 
           339  Strain relief 
           340  Headphone cable 
           350  Microphone housing 
           352  Cable bushing 
           360  Microphone cable 
           370  Switch box 
           372 - 376  Cable connectors 
           378  Control dial 
           380  Conference connection cable 
           400  Headset 
           410  Voice microphone wire 
           412  Ambient microphone wire 
           418  Speaker wire 
           430  Earpiece 
           432  Housing 
           434  Ear adapter 
           436  Air duct 
           440  Hinge 
           450  Mouthpiece 
           452  Microphone mount 
           452   a ,  452   b  Perforation 
           454  Arm 
           460  Rear earpiece 
           470  Connecting piece 
           480  Switch module 
           482  Antenna block 
           484  Control signal block 
           490  Button panel 
           492  Control signal wire 
           500  Headset 
           530  Listening unit, left 
           532  Earpiece 
           534  Grip 
           536  Earpiece cable, left 
           539  Bundling ring 
           540  Listening unit, right 
           542  Earpiece 
           544  Grip 
           546  Earpiece cable, right 
           550  Voice unit 
           552  Housing 
           552   a ,  552   b  Perforation 
           554 ,  555  Cable bushing (strain relief) 
           556 ,  357  Button 
           558  Adjustment wheel 
           560  Control board 
           570  Connection cable 
           572  Plug 
         a, b, ab Signal inputs 
         x Signal output 
         AGC Automatic Gain Control 
         EC Echo Cancellation 
         G(f), G l (f), G r (f) Attenuation function 
         R 1 , R 2  Attenuation values 
         S c , S c1 -S c6  Control signals 
         S EC  Echo compensation signal 
         S H  Listening signal 
         S H,l  Listening signal, left 
         S H,r  Listening signal, right 
         S in  Received signal 
         S M  Voice signal 
         S N  (General) ambient signal 
         S N,l  Ear signal (specific ambient signal), left 
         S N,r  Ear signal (specific ambient signal), right 
         S out  Transmission signal 
       
     
         [0238]    The above list of reference numbers and symbols is an integral part of the description.