| 摘要 |
PURPOSE:To realize a portable loud speaker device, which has a high S/N is less deteriorated in sound quality by reverberation and is difficult to cause a howling by providing an oscillator to oscillate at above 10kHz, and an adding means to add an oscillator output and a microphone output. CONSTITUTION:The oscillator 5 to perform oscillation higher than 10kHz and the adding means 6 to add the oscillator 5 output and the microphone 1 output are provided. Thus, since a signal is inputted to an amplifier 3 even in a state that the microphone 1 output does not exist, the amplifier 3 never operates unstable operation, and a part of a noise from the inner part or the external part of the amplifier 3 is absorbed in the signal higher than 10kHz, and the S/N is improved, and further, a transitional characteristic in a speaker 4 is improved, and the reverberation decreases and the howling comes difficult to occur. |
