抄録
In our daily lives, the sound masking method is used for protecting privacy of conversation at public open space such as the pharmacy or the bank counters. The approach of the sound masking method is to cover contents of conversation by using the masking sound. This masking sound which is generated from a loudspeaker allow a third party not to understand what is said. However, there is a problem that the sound level is increased too much because of the unnecessary power of the masking sound. Accordingly, in order to decrease the total sound level, the authors have attempted to use active noise control (ANC) technique during the sound masking is conducted. This paper describes the fundamental study on the character of the masking sound. The objective of the proposed masking sound is to make it difficult to understand the contents of conversation with sound pressure as small as possible. Furthermore, the effectiveness of ANC technique is shown by the experiment.
