SOUND DEVICE, NOISE SOUND CONTROL METHOD, NOISE SOUND CONTROL PROGRAM, AND RECORDING MEDIUM

摘要

When the signal level of the signal AOD to which the cancellation signal CND of the audio signal ACD is added is higher than the signal level of the audio signal ACD, the change rate calculation unit 173 indicates that the degree of noise cancellation should be the highest. Therefore, the maximum value (= 1) is calculated as the change rate parameter. On the other hand, when the signal level of the signal AOD obtained by adding the cancellation signal CND of the audio signal ACD is smaller than the signal level of the audio signal ACD, the change rate calculation unit 173 increases the noise level as the difference between the two signal levels increases. A change rate parameter is calculated to indicate that the degree of cancellation is low. Then, the cancel signal generation unit 175 generates a cancel signal CND while considering the value of the change rate parameter, and sends it to the addition unit 171. As a result, appropriate noise sound control can be easily performed.