| 摘要 |
PROBLEM TO BE SOLVED: To provide a loop gain estimating apparatus capable of estimating a loop gain even if the environment of a closed loop is changed, in order to prevent occurrence of howling in advance. SOLUTION: A pseudo noise superimposition portion 7 superimposes pseudo noise (M-sequence) onto sound picked up by a microphone 11 and outputs it to an amplification section. An operation portion 5 computes correlation between the sound picked up by the microphone 11 and the pseudo noise. The operation portion 5 estimates the loop gain, using a first computed correlation value greater than or equal to a predetermined level after the pseudo noise superimposition portion 7 outputs pseudo noise, as a component of a direct wave. COPYRIGHT: (C)2010,JPO&INPIT |
