# Patent

## Title
System, method and program for controlling mute function on telephone

## Abstract

System, method and program for controlling a mute function on a telephone device. While the mute function is active, sound reaching a telephone or other communication device is sensed, and a determination is made if the sound includes a word. If so, an alarm is activated to alert a user that the mute function is active. If not, the alarm is not activated. In accordance with an optional feature of the present invention, speech recognition software is trained to recognize the voice or speech pattern of a specific user, and the alarm is activated only if the word was spoken by the specific user.

## Background
FIELD OF INVENTION
The present invention relates generally to telephones, and more particularly to control of a mute function on a telephone or other audio communication device.
BACKGROUND
It is known for a telephone to include a mute function, typically activated by a user pressing a mute button on the telephone. Once the mute function is activated, speech or other sounds reaching the telephone will not pass through to other people on a call. The mute function is typically (but not always) used when the telephone is operating in a “speaker” mode, where a microphone in the telephone base unit is activated (instead of a microphone in the handset). The mute function is typically used in a conference call at times when the user is not expected to speak, although it could be used as well in a call with only one other person. Occasionally, while the mute function is active, the user will attempt to speak to the other person or people on the call, forgetting that the mute function is active. Because mute function is active, the other person or people will not hear the words spoken by the user. When the user realizes that the mute function is active, the user will need to repeat the previously muted words.
U.S. Pat. No. 6,870,919 discloses a telephone with a mute function, and a notification unit which determines when a user is speaking while the mute function is active. In such a case, the telephone or a computer provides a mute status reminder to the user. The mute status reminder may be a tone or prerecorded message. U.S. Pat. No. 6,870,919 also discloses activation of the mute status reminder when the communication signal exceeds a predetermined energy level.
An object of the present invention is to avoid unnecessary mute status reminders.
SUMMARY
The present invention resides in a system, method and program for controlling a mute function on a telephone device. While the mute function is active, sound reaching a telephone or other communication device is sensed, and a determination is made if the sound includes a word. If so, an alarm is activated to alert a user that the mute function is active. If not, the alarm is not activated.
In accordance with an optional feature of the present invention, speech recognition software is trained to recognize the voice or speech pattern of a specific user, and the alarm is activated only if the word was spoken by the specific user.



BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of a telephone with a hand set, base unit with a microphone/speaker, mute button and internal function to provide a mute status reminder with controls according to the present invention.
FIG. 2 is a block diagram of certain components of the telephone of FIG. 1.
FIG. 3 is a flow chart of one embodiment of the mute status reminder function of FIG. 1.
FIG. 4 is a flow chart of another embodiment of the mute status reminder function of FIG. 1.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described in detail with reference to the figures. FIG. 1 illustrates a telephone generally designated 10 in which the present invention is incorporated. Telephone 10 comprises a conventional handset 12 with a microphone 14 at one end and a speaker 16 at the other end. As shown, the handset 12 resides in its well in a base unit 22, and is not in use. Telephone 10 also comprises another speaker 18 and another microphone 20 in base unit 22, which are used in a hands-free, “speakerphone” mode. Telephone 10 also comprises conventional alphanumeric keys 30 to enter a telephone number for a call, and conventional speakerphone mode button 31. If desired, telephone 10 can also include other conventional telephone features, unrelated to the present invention. Telephone 10 also includes a mute button 32 with internal mute status reminder function according to the present invention, as described below.
FIG. 2 illustrates some functional components/modules of the base unit 22 of telephone 10. In the illustrated embodiment, microphone 20 in base unit 22 is active regardless of whether the telephone 10 is operating in the “speakerphone” mode and regardless of whether the mute button 32 is active/set. Microphone 20 detects speech and other sounds that reach it. The other sounds can be background sounds such as a door opening or closing, keys of a computer keyboard being pressed, a chair moving, air conditioning noise, etc. Microphone 20 converts the speech and other sounds it detects into corresponding, electrical analog signals, in a known manner. If the mute button 32 is not active/not set, a known communication module 39 processes these analog signals in a known manner for communication to other people, via a telephone line 35, connected with a telephone call. However, if the mute button 32 is active/set, then the communication module 39 will be disabled, and not process or communicate these analog signals to other people connected with the telephone call. For those embodiments of the present invention comprising computer software, telephone 10 includes a CPU 36 and basic operating system function 39 to execute the software, RAM 37 and ROM 38 to store speech recognition software 45 prior to execution by CPU 36 via RAM 37.
In accordance with the present invention, a threshold detection module 40 compares, to a predetermined threshold, energy level or magnitude of the analog signals from the microphone 20. The threshold detection module 40 may comprise an integrated circuit or other circuitry and/or a computer program stored on ROM 38 for execution by processor 36 via RAM 37. If the analog signal level is below the threshold, the source of the sounds is presumed to be background noise, and threshold detection module 40 will deactivate an audio alarm 54. (In such a case in a hardware embodiment of the present invention, threshold detection module 40 sends a “low” signal to AND gate 43, whose output is connected to an “Activate” input of audio alarm 54.) However, if the analog signal level is above the threshold, then the threshold detection module will permit activation of the audio alarm 54 (if other conditions, described below, are met). (In a hardware embodiment of the present invention, threshold detection module 40 sends a “high” signal to AND gate 43 to permit activation of audio alarm 54.) A speech recognition module 44, which is software executing on processor 36, an integrated circuit and/or other circuitry, also analyzes the analog signal from the microphone 20. In accordance with one embodiment of the present invention, the speech recognition module 44 attempts to recognize any words (in any human voice) in the analog signal, using known speech recognition algorithms embodied in the software, integrated circuit and/or other circuitry. By way of example, IBM ViaVoice speech recognition software contains algorithms to perform speech recognition. Also, CMU Sphinx-III voice recognition software and VoiceSignals voice recognition software contain speech recognition algorithms/modules based on hidden-markov model (HMM) representations of language. Such known speech recognition software programs can be used in module 44 to attempt to recognize words and/or speech patterns in the analog signals. If the speech recognition module 44 does not identify any words in the analog signal, the speech recognition module 44 presumes the analog signal to represent background noise and not an attempt by the user to communicate to the other person or people on the call. Consequently, the speech recognition module 44 will deactivate the audio alarm 54. (In a hardware embodiment of the present invention, in such a case, speech recognition module 44 sends a “low” signal to AND gate 43.) However, if the speech recognition module 44 identifies any words (in any human voice) from the analog signal, then the speech recognition module 44 will permit activation of the audio alarm 54 to attempt to alert the user that the mute button is active/set. (In a hardware embodiment of the present invention, in such a case, speech recognition module 44 sends a “high” signal to AND gate 43.) This signal will activate the audio alarm 54 if the threshold detection module detected that the signal level exceeded the threshold level and mute button 32 has been activated/set and has enabled audio alarm 44. The reason that speech recognition module 44 attempts to activate the audio alarm (when it identifies one or more spoken words) is the presumption that the user of telephone 10 spoke the word(s) and intended to communicate the word(s) to the other person or people on the telephone call. Upon hearing the alarm, the user will typically deactivate/reset the mute button and repeat the words that were previously muted. Because the audio alarm will sound near the beginning of the user's speech (as soon as the speech recognition module 44 detects the first word or two), the user can deactivate/reset the mute button near the beginning of the user's speech, and may only have to repeat a few words. As noted above, if the mute button is active/set, but the speech recognition module 44 does not identify any words from the analog signal, then the speech recognition module 44 will not attempt to activate the audio alarm 54 and not alert the user that the mute button is active/set. The reason that the module 44 will not attempt to activate the audio alarm 54 in this case is the presumption that the sounds were background noise, and not intended as a communication from the user. If the mute button is not active/not set, the state of the mute button (switch) will disable the audio alarm 54, and will not permit the audio alarm to sound under any circumstances. This will avoid interfere with the user's attempts to communicate with the other person or people on the call.
In accordance with another embodiment of the present invention, the speech recognition module 44 not only recognizes words but also has been trained to recognize the voice of the user (of telephone 10) and distinguish words spoken by the user from the same words spoken by other people. By way of example, a specific user can train a known ARM processor-based speech recognition program (such as IBM Via Voice speech recognition software based on Hidden Markov Model) to recognize the specific user's speech pattern, and differentiate it from other background noise or other people's speech patterns. A “speech pattern” is the spectra of electrical signals generated by a microphone when a specific person speaks words. More information on this speech recognition program can be obtained from manufacturer's manuals such as that from VoiceSignal company at Http://www.voicesignal.com/solutions/tech.php3# sda.
This embodiment of the present invention operates the same as the foregoing embodiment described above, except that the speech recognition module 44 only attempts to actives the audio alarm 54 if the speech recognition module 44 detects, in the analog signal, a word or speech pattern spoken in the voice of the user. This will avoid unnecessary audio alarms in cases where another person is speaking in the vicinity of the telephone. For example, there may be a secretary near the user or someone walking by the user, and the secretary or other person is speaking loudly enough to be detected by microphone 20 and exceed the threshold level of module 40. This will not cause the speech recognition module 44 to attempt to activate the audio alarm in this embodiment of the present invention. The audio alarm is not needed or desired in such cases because the secretary or other person do not intend to communicate to the other people on the telephone call, and therefore, there is no need to alert the user of telephone 10 that the mute function is active/set.
FIG. 3 is a flow chart based on a combined hardware and software embodiment of threshold detection module 40 and speech recognition module 44. Threshold detection module 40 comprises a threshold detector 41 to determine whether the analog signal exceeds a threshold, and logic 42 to process the output of the threshold detector 41. In this embodiment, detector 42 is formed from circuitry, and logic 42 is formed from computer programming. Speech recognition module 44 comprises a speech recognition function 45 to recognize spoken words represented by the analog signal, and logic 46 to process the output of the speech recognition function 45. In this embodiment, speech recognition function 45 comprises circuitry and/or computer programming, and logic 46 comprises computer programming. FIG. 3 is a flowchart of the program logic 42 and program logic 46 in this embodiment of the present invention. Because threshold detector 41 and speech recognition function 45 are well known, their mode of operation need not be repeated in detail herein. In step 100, logic 42 within the threshold detection module 40 receives a signal from threshold detector 41. The signal from threshold detection function 41 indicates whether the power level, energy level or magnitude of the analog signal corresponding to the speech or other sounds detected by the microphone 20 exceeds a predetermined threshold level. If not (decision 104, no branch), then logic 42 will not permit activation of the audio alarm 54 (step 106). If so (decision 104, yes branch), the first test for activating the audio alarm 54 is met, and the analysis of whether to activate the alarm proceeds to the next test. Accordingly, logic 46 within the speech recognition module 44 has also received a signal from the speech recognition function 45 indicating whether the speech recognition function 45 has detected a real word in the analog signal (step 108). If not (decision 110, no branch), then logic 46 will send a deactivation signal to audio alarm 54 to prevent the audio alarm from sounding (step 112). If so (decision 110, yes branch), then the second test for activating the audio alarm is met, and the speech recognition logic 46 sends an activation signal to the audio alarm 54 (step 118). If the mute button has been activated/set enabling the audio alarm 54, then the activation signal from the logic 46 will cause the audio alarm 54 to sound its alarm. However, if the mute button has not been activated/set, then the audio alarm 54 will not be enabled and will not sound its alarm in response to the activation signal from the speech recognition logic 46.
FIG. 4 is a flow chart based on a combined hardware and software embodiment of threshold detection module 40 and a speech recognition module 144 (that substitutes for module 44 in FIGS. 1 and 2). Threshold detection module 40 comprises threshold detector 41 to determine whether the analog signal exceeds a threshold, and logic 42 to process the output of the threshold detector 41. In this embodiment (as in the previous embodiment), detector 41 is formed from circuitry, and logic 42 is formed from computer programming. Speech recognition module 144 comprises a speech recognition function 145 to recognize words spoken by a specific person, and logic 146 to process the output of the speech recognition function 145. In this embodiment, speech recognition function 145 comprises circuitry and/or computer programming, and logic 146 comprises computer programming. FIG. 4 is a flowchart of the program logic 42 and program logic 146 in this embodiment of the present invention. Because threshold detector 41 and speech recognition function 145 are well known, their modes of operation need not be repeated in detail herein. In step 200, logic 42 within the threshold detection module 40 receives a signal from threshold detector 41. The signal from threshold detection module 40 indicates whether the power level, energy level or magnitude of the analog signal corresponding to the speech or other sounds detected by the microphone 20 exceeds a predetermined threshold level. If not (decision 204, no branch), then logic 42 will not permit activation of the audio alarm 54 (step 206). If so (decision 204, yes branch), the first test for activating the audio alarm 54 is met, and the analysis of whether to activate the alarm proceeds to the next test. Accordingly, logic 146 within the speech recognition module 144 has also received a signal from the speech recognition function 145 indicating whether the speech recognition function 145 has detected a real word in the analog signal from a specific person/recognized user (step 208). This is the person/user who has trained the speech recognition function 145 to recognize this person's/user's voice and distinguish this person's/user's voice from other people's voices. (Speech recognition function 145 will not send a signal to logic 146 indicating that it has detected a real word in the specific person's/user's voice when it detects a real word from another person or when it detects only background/nonword sounds.) If the speech recognition function 145 has not detected a real word or speech pattern in the analog signal from a specific person/recognized user (decision 210, no branch), then logic 146 will deactivate audio alarm 54 so it cannot sound (step 212). However, if the speech recognition function 145 has detected a real word or speech pattern in the analog signal from the specific person/recognized user (decision 210, yes branch), then the second test for activating the audio alarm is met, and the speech recognition logic 146 sends an activation signal to the audio alarm 54 (step 218). If the mute button has been activated/set, then the audio alarm 54 is enabled and the activation signal from the speech recognition logic 146 will cause the audio alarm 54 to sound. However, if the mute button has not been activated/set, then the audio alarm 54 will not be enabled and will not sound the alarm in response to the activation signal from the speech recognition logic 146.
Based on the foregoing, system, method and computer program for implementing a mute function have been disclosed. However, numerous modifications and substitutions can be made without deviating from the scope of the present invention. For example, the speech recognition software can be programmed to disable the mute function if the user commands such disabling by spoken words. Therefore, the present invention has been disclosed by way of illustration and not limitation, and reference should be made to the following claims to determine the scope of the present invention.

## Claims

1. A method for controlling a mute function in a telephone device, said method comprising the steps of:
while the mute function is active, a microphone in the telephone device sensing sound reaching said telephone device, and voice recognition software in said telephone device recognizing and identifying a specific word from said sound sensed by said microphone while said mute function is active, and in response, said telephone device automatically activating an alarm in said telephone device to alert a user that said mute function is active;
said voice recognition software training to differentiate a specific word spoken by a specific person from a same specific word spoken by other people; and
while the mute function is active, said voice recognition software processing other sound detected by said microphone to recognize and identify said specific word spoken by said specific person and not by another person, and in response, said telephone device activating said alarm.

2. A telephone device including a mute function, said telephone device comprising:
a microphone for sensing sound reaching said telephone device;
a CPU, a memory and a computer readable storage device;
a voice recognition program, stored in said storage device for execution by said CPU via said memory, to recognize and identify specific words from sound sensed by said microphone while said mute function is active; and
computer hardware and/or software stored in said storage device for execution by said CPU via said memory, operative while said mute function is active, (a) responsive to said voice recognition program recognizing and identifying a specific word from said sound sensed by said microphone while said mute function is active, to activate an alarm in said telephone device to alert a user that said mute function is active, and (b) responsive to said voice recognition program not recognizing and identifying a specific word from said sound sensed by said microphone while said mute function is active, to avoid activation of said alarm; and wherein:
said voice recognition program has been trained to differentiate a specific word spoken by a specific person from a same specific word spoken by other people; and
said voice recognition program processes other sound detected by said microphone while said mute function is active to recognize and identify said specific word spoken by said specific person and not by another person, and said computer hardware and/or software is responsive to said voice recognition program recognizing and identifying said specific word spoken by said specific person and not by another person, to activate said alarm.

3. A computer program product for controlling a mute function of a telephone device equipped with a microphone to detect sound reaching the telephone device, said computer program product comprising:
a computer readable storage device;
a voice recognition program, operative while a mute function is active, to recognize and identify specify words from sound detected by said microphone;
program instructions, operative while said mute function is active, (a) responsive to said voice recognition software recognizing and identifying a specific word from said sound sensed by said microphone while said mute function is active, to activate an alarm to alert a user that said mute function is active, and (b) responsive to said voice recognition program not recognizing and identifying a specific word from said sound sensed by said microphone while said mute function is active, to avoid activation of said alarm; and wherein
said voice recognition program and said program instructions are stored on said computer readable storage device; and wherein:
said voice recognition program has been trained to differentiate a specific word spoken by a specific person from a same specific word spoken by other people; and
said voice recognition program processes other sound detected by said microphone while said mute function is active to recognize and identify said specific word spoken by said specific person and not by another person, and said program instructions are responsive to said voice recognition program recognizing and identifying said specific word spoken by said specific person and not by another person, to activate said alarm.