A control unit of a telephone device is configured to perform a first processing of: estimating a line echo amount based on a volume of a DTMF signal generated by a DTMF signal generation unit and a volume of the DTMF signal input from a line; calculating a howling noise threshold value based on the maximum value of the acoustic echo generated at a handset that is measured in advance and set values of a sidetone volume, a transmission volume, and a reception volume; and calculating a difference between the line echo amount and the howling noise threshold value as an adjustment requisite amount and lowering the set value of the sidetone volume by the adjustment requisite amount when the line echo amount is larger than the howling noise threshold value.

A control unit of a telephone device is configured to perform a first processing of: estimating a line echo amount based on a volume of a DTMF signal generated by a DTMF signal generation unit and a volume of the DTMF signal input from a line; calculating a howling noise threshold value based on the maximum value of the acoustic echo generated at a handset that is measured in advance and set values of a sidetone volume, a transmission volume, and a reception volume; and calculating a difference between the line echo amount and the howling noise threshold value as an adjustment requisite amount and lowering the set value of the sidetone volume by the adjustment requisite amount when the line echo amount is larger than the howling noise threshold value.

A communication device and an output sidetone adjustment method thereof are disclosed. The method includes the steps of: receiving a far-end sound; receiving a near-end sound to form a sidetone and obtaining an average input volume of the near-end sound; detecting ambient noise of the near-end sound; analyzing an average noise volume and a noise frequency band of the ambient noise to determine whether the average noise volume of the ambient noise is higher than the average input volume; if yes, adjusting the volume of the sidetone in a specific frequency band by increasing it by a first gain value to form an adjusted sidetone, wherein the specific frequency band and the noise frequency band of the ambient noise belong to the same frequency band or different frequency bands; and outputting the adjusted sidetone and the far-end sound.

A communication device and an output sidetone adjustment method thereof are disclosed. The method includes the steps of: receiving a far-end sound; receiving a near-end sound to form a sidetone and obtaining an average input volume of the near-end sound; detecting ambient noise of the near-end sound; analyzing an average noise volume and a noise frequency band of the ambient noise to determine whether the average noise volume of the ambient noise is higher than the average input volume; if yes, adjusting the volume of the sidetone in a specific frequency band by increasing it by a first gain value to form an adjusted sidetone, wherein the specific frequency band and the noise frequency band of the ambient noise belong to the same frequency band or different frequency bands; and outputting the adjusted sidetone and the far-end sound.

A communication device and a sidetone volume adjusting method thereof are disclosed. The communication device includes a sound processor, a far-end sound receiver, a near-end sound receiver, a volume adjuster, and a sound player. The far-end sound receiver is configured to receive a far-end sound and transmit it to the sound processor. The near-end sound receiver is configured to receive a near-end sound such that the sound processor receives the near-end sound to form a sidetone. The volume adjustment module is configured to adjust the volume of the far-end sound and the sidetone to form the adjusted far-end sound and the adjusted sidetone, wherein the volume of the adjusted sidetone is based on the near-end sound and the adjusted far-end sound. The sound player is used to play the adjusted sidetone and the adjusted far-end sound.

A communication device and an output sidetone adjustment method thereof are disclosed. The method includes the steps of: receiving a far-end sound; receiving a near-end sound to form a sidetone and obtaining an average input volume of the near-end sound; detecting ambient noise of the near-end sound; analyzing an average noise volume and a noise frequency band of the ambient noise to determine whether the average noise volume of the ambient noise is higher than the average input volume; if yes, adjusting the volume of the sidetone in a specific frequency band by increasing it by a first gain value to form an adjusted sidetone, wherein the specific frequency band and the noise frequency band of the ambient noise belong to the same frequency band or different frequency bands; and outputting the adjusted sidetone and the far-end sound.

A communication device and an output sidetone adjustment method thereof are disclosed. The method includes the steps of: receiving a far-end sound; receiving a near-end sound to form a sidetone and obtaining an average input volume of the near-end sound; detecting ambient noise of the near-end sound; analyzing an average noise volume and a noise frequency band of the ambient noise to determine whether the average noise volume of the ambient noise is higher than the average input volume; if yes, adjusting the volume of the sidetone in a specific frequency band by increasing it by a first gain value to form an adjusted sidetone, wherein the specific frequency band and the noise frequency band of the ambient noise belong to the same frequency band or different frequency bands; and outputting the adjusted sidetone and the far-end sound.

A control unit of a telephone device is configured to perform a first processing of: estimating a line echo amount based on a volume of a DTMF signal generated by a DTMF signal generation unit and a volume of the DTMF signal input from a line; calculating a howling noise threshold value based on the maximum value of the acoustic echo generated at a handset that is measured in advance and set values of a sidetone volume, a transmission volume, and a reception volume; and calculating a difference between the line echo amount and the howling noise threshold value as an adjustment requisite amount and lowering the set value of the sidetone volume by the adjustment requisite amount when the line echo amount is larger than the howling noise threshold value.

Described is an echo cancellation method including buffering the at least one frame of a first voice signal, the at least one frame of the first voice signal including an echo signal, when the at least one frame of signal is preprocessed, separately obtaining, in a first timing period, the at least one frame of the first voice signal from a buffer and at least one frame of a reference signal matching the at least one frame of first voice signal from a reference signal queue, so that an estimated latency value, between each frame of first voice signal and a corresponding reference signal, remains within a preset range, performing echo cancellation processing on the echo signal in the at least one frame of first voice signal using the at least one frame of reference signal, to obtain a second voice signal, and outputting the second voice signal.

The technology described in this document can be embodied in a method that includes receiving, at one or more processing devices of a headset that includes a sidetone generation circuit, an input signal representing ambient audio, and determining, by the one or more processing devices of the headset, that at least a portion of the input signal represents voice activity that satisfies a threshold condition. The method also includes, responsive to determining that the voice activity in the input signal satisfies the threshold condition, a control signal configured to cause the sidetone generation circuit to generate sidetone signals, and generating, by an acoustic transducer of the headset, an audio signal that represents, at least in part, the sidetone signals generated in accordance with the control signal.