Echo suppressing apparatus, echo suppressing system, echo suppressing method and recording medium

An echo suppressing system, comprising:

• a sound output device for outputting a sound based on a reference sound signal;
• a sound processing device for processing a observed sound signal based on a received sound;
• and
• an echo suppressing apparatus for suppressing a echo component of the observed sound signal, wherein the echo suppressing apparatus comprises:
• an echo removal section for presuming an echo component of the observed sound signal on the basis of both the observed sound signal and the reference sound signal, and removing the echo component from the observed sound signal;
• a ratio calculation section for calculating a power ratio of the observed sound signal to the reference sound signal;
• a correction amount calculation section for calculating, in accordance with the calculated power ratio, a correction amount for the observed sound signal from which the echo component is removed;
• a correction section for correcting, based on the calculated correction amount, the observed sound signal from which the echo component is removed, so as to suppress a residual echo remaining in the observed sound signal from which the echo component is removed;
• and
• an output section for outputting the corrected observed sound signal to the sound processing device.

An echo suppressing method for making an echo suppressing apparatus operable with a sound output device for outputting sound based on a reference sound and a sound processing device for processing a observed sound signal based on a received sound, suppress an echo of the observed sound signal, the echo suppressing method comprising:

• presuming an echo component of the observed sound signal on the basis of both the observed sound signal and the reference sound signal output from the sound output device;
• removing the echo component from the observed sound signal;
• calculating a power ratio of the observed sound signal to the reference sound signal;
• calculating, in accordance with the calculated power ratio, a correction amount for the observed sound signal from which the echo component is removed;
• correcting, based on the calculated correction amount, the observed sound signal from which the echo component is removed, so as to suppress a residual echo remaining in the observed sound signal from which the echo component is removed;
• and
• outputting the corrected observed sound signal to the sound processing device.

A computer-readable recording medium recording a program is recorded for making the computer operable with a sound output device for outputting sound based on a reference sound signal and a sound processing device for processing a observed sound signal based on a received sound, calculate a correction amount for correcting the observed sound signal, the program comprising:

• presuming a echo component of the observed sound signal on the basis of both the observed sound signal and the reference sound signal;
• removing the echo component from the observed sound signal;
• calculating a power ratio of the observed sound signal to the reference sound signal;
• and
• calculating, in accordance with the calculated power ratio, a correction amount for the observed sound signal from which the echo component is removed.