To provide an adaptive sound quality and sound volume controller with which a user can naturally listen to in hearing sense even when the level of the sound source signal changes rapidly.

This sound quality and sound volume controller 30 is provided with a microphone 36 for collecting ambient sound obtained by amplifying the sound source signal, a controlling part 40 for calculating the adjustment quantity of a signal level adjusting part 33 and a frequency characteristic adjusting part 32 on the basis of a collected sound signal and the sound source signal collected by the microphone 36 in every prescribed period of time and controlling the adjustment quantity, a sound source signal level fluctuation detecting part 50 for detecting the change of the signal level of the sound source signal, and an operation time interval calculating part 51 for controlling the operation time interval of the controlling part 40 on the basis of the change of the signal level of the sound source signal detected by the detecting part 50.