Patent ID: 8428274

Claim:
An acoustic-feedback detection apparatus comprising: first level detecting means for detecting a first signal level of sound signals obtained from a position in a sound-signal system in which a microphone and speaker are connected; extracting means for extracting, from the sound signals of which the first signal level is detected, signals in a band having a bandwidth predetermined for each of at least one predetermined center frequency; second level detecting means for detecting a second signal level of the signals in each band, the signals being extracted by the extracting means; determining means for determining whether or not acoustic feedback is occurring based on a threshold determined according to the first signal level detected by the first level detecting means and a waveform of each second signal level detected by the second level detecting means; third level detecting means for detecting a third signal level of external sound signals to be supplied to a position in the sound-signal system; second extracting means for extracting, from the external sound signals, signals in the band having the bandwidth predetermined for each of the at least one center frequency; and fourth level detecting means for detecting a fourth signal level of the signals in each band, the signals being extracted by the second extracting means; wherein the determining means determines whether or not acoustic feedback is occurring based on a first output resulting from the detection performed by the third level detecting means and a second output resulting from the detection performed by the fourth level detecting means.