Audio system

An audio system comprising:

• a first-seat speaker positioned near a first seat in an automobile;
• a microphone positioned near a head of a user sitting in the first seat;
• a second-seat speaker positioned near a second seat in the automobile;
• a first-seat audio source configured to output a first audio signal;
• a masking noise source configured to output a predetermined noise signal as a masking noise signal;
• a second-seat audio source configured to output a second audio signal to be emitted from the second-seat speaker;
• and
• audio signal processing circuitry configured to:
• extract a cross-talk signal, the cross-talk signal being a component of the second audio signal included in an output of the microphone;
• extract a noise signal from the output of the microphone, the noise signal not including the component of the second audio signal or a component of a sound emitted from the first-seat speaker, and including a noise component that does not relate to the audio system;
• determine an amount of gain adjustment for the masking noise signal such that the masking noise signal is at a predetermined level greater than a difference in magnitude between the cross-talk signal and the noise signal;
• perform gain adjustment to adjust a gain of the masking noise signal output from the masking noise source based on the determined amount of gain adjustment;
• and
• generate a combined signal by combining the masking noise signal after the gain adjustment and the first audio signal output from the first-seat audio source together, and output the combined signal to the first-seat speaker.