摘要 |
A mute unit 20 is attached to a trumpet. Inside the mute unit 20, a microphone 21 is mounted, so that a sound collected by the microphone 21 is converted to an electric signal. The electric signal is supplied to a signal processor 30. The signal processor 30 processes the electric signal converted by the microphone 21 such that changes in frequency characteristic of the sound caused by the mute unit 20 are cancelled. The signal processor 30 then outputs the processed signal. |