Sound reproduction appts. esp. for vehicle radio or cassette player

摘要

The appts. has a sound source (101) for generating a sound signal. A sound reproduction device generates and transmits the sound into a compartment of the vehicle, from the sound signal. A microphone (106) is provided in this compartment of the vehicle. The microphone provides an indication of the sound transmitted into the vehicle compartment and from the surrounding noise, and provides a sound indication signal. An indicator shows the amplitude of the surrounding noise by showing as difference between the amplitude of the sound signal and the sound indication signal. A volume control (103) controls the volume of the sound signal in accordance with the level of the surrounding noise from the indicator.