Method and apparatus for detecting speech at a near-end of a communications system, a speaker-phone system, or the like
First Claim
1. A speaker-phone system for communication between a near-end terminal and a far-end terminal, comprising:
- an acoustic speaker at the near-end terminal;
a receiver for receiving a first signal from the far-end terminal for driving the acoustic speaker;
a microphone for converting an acoustic signal at the near-end terminal to a second signal to be transmitted, the microphone being acoustically coupled to the acoustic speaker at the near-end terminal;
a transmitter for transmitting said second signal to be transmitted to the far-end terminal;
a first circuit for providing a fixed frequency content to said first, received signal in a frequency range that may be contained in said signal to be transmitted, the first circuit including a filter for removing from the first, received signal at least one frequency that is contained in the signal received from the far-end terminal to provide the fixed frequency content;
a detector to detect the presence of a modification of said known frequency content in said second signal to be transmitted, the detector including a power detector for detecting signal power at the at least one frequency removed from the first, received signal; and
a control circuit connected to the first circuit and the detector to modify at least one parameter of the speaker-phone system when said detector detects a long term power level greater than a noise floor in the second signal to be transmitted at the at least one frequency removed from the first, received signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and communication system (10), which can be used in a full, pseudo full, or half duplex speaker-phone system, includes a circuit (14) to remove a frequency component from a received signal to output a modified received signal, and a speaker (18) to convert the modified received signal to an acoustic signal (20). The circuit (14) may be, for example, a notch filter, which may remove a sharp frequency range between about 1250 Hz and 1550 Hz. A microphone (26) converts a second acoustic signal (24) to an electrical signal for transmitting, and a detector (30) produces a detector output if the removed frequency is present in the acoustic signal (24). A circuit (34) is also provided to modify a circuit parameter applied to the received signal when the detector (30) produces a detector output. The parameter may be, for instance an attenuation applied to the received signal.
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Citations
38 Claims
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1. A speaker-phone system for communication between a near-end terminal and a far-end terminal, comprising:
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an acoustic speaker at the near-end terminal; a receiver for receiving a first signal from the far-end terminal for driving the acoustic speaker; a microphone for converting an acoustic signal at the near-end terminal to a second signal to be transmitted, the microphone being acoustically coupled to the acoustic speaker at the near-end terminal; a transmitter for transmitting said second signal to be transmitted to the far-end terminal; a first circuit for providing a fixed frequency content to said first, received signal in a frequency range that may be contained in said signal to be transmitted, the first circuit including a filter for removing from the first, received signal at least one frequency that is contained in the signal received from the far-end terminal to provide the fixed frequency content; a detector to detect the presence of a modification of said known frequency content in said second signal to be transmitted, the detector including a power detector for detecting signal power at the at least one frequency removed from the first, received signal; and a control circuit connected to the first circuit and the detector to modify at least one parameter of the speaker-phone system when said detector detects a long term power level greater than a noise floor in the second signal to be transmitted at the at least one frequency removed from the first, received signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A speaker-phone system for communication between a near-end terminal and a far-end terminal, comprising:
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an acoustic speaker at the near-end terminal; a receiver for receiving a first signal from the far-end terminal for driving the acoustic speaker; a microphone for converting an acoustic signal at the near-end terminal to a second signal to be transmitted, the microphone being acoustically coupled to the acoustic speaker at the near-end terminal; a transmitter for transmitting said second signal to be transmitted to the far-end terminal; a filter for removing from the first, received signal at least one frequency that is contained in said second signal to be transmitted; a detector to detect the presence of said at least one frequency in said second signal to be transmitted; and a control circuit connected to modify at least one parameter of the speaker-phone system when said detector detects the presence of said at least one frequency in said second signal to be transmitted. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A method for operating a speaker-phone system for communication between a near-end terminal and a far-end terminal, said speaker-phone system having an acoustic speaker at the near-end terminal, a receiver for receiving a first, received signal from the far-end terminal for driving the acoustic speaker, a microphone for converting an acoustic signal at the near-end to a converted signal to be transmitted, the microphone being acoustically coupled to the speaker at the near-end terminal, and a transmitter for transmitting said converted signal to the far-end terminal, comprising:
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removing a known content from said first, received signal within a frequency range that is contained in said converted signal; detecting the presence of a change to said known content in said converted signal; and modifying at least one parameter of the speaker-phone system when said change to said known content is detected in said converted signal. - View Dependent Claims (23, 24, 25, 26, 27, 28)
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29. A communication system, comprising:
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a circuit for removing a frequency component from a received signal to output a modified received signal; a speaker for converting the modified received signal to an acoustic signal; a microphone, acoustically coupled to the speaker, for converting an acoustic signal to an electrical signal for transmitting; a detector for producing a detector output if said removed frequency is present in said acoustic signal; and a circuit for modifying a circuit parameter applied to said received signal when said detector produces a detector output. - View Dependent Claims (30, 31, 32, 33, 34)
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35. A method for processing communication signals, comprising:
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removing a frequency component from a received signal to produce a modified received signal; converting the modified received signal to a first acoustic signal; converting a second acoustic signal to an electrical signal for transmitting, said second acoustic signal containing said first acoustic signal; and modifying circuit parameters applied to said received signal if said frequency component is present in said acoustic signal. - View Dependent Claims (36, 37, 38)
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Specification