| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To make it difficult to recognize an unnecessary signal included in an audio signal by a device with a simple configuration. <P>SOLUTION: An additional signal stored in a signal storage device 4 is always added to an audio signal obtained by a sound collecting device 1. In the signal storage device, a plurality of additional signals are stored and under control based upon settings by a control circuit 8, an additional signal to be added to the audio signal can be selected. The additional signal is preferably a signal having a 200 to 4 kHz center frequency or a white noise signal which is a signal whose sound pressure level is within a given range. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
