Audio signal processing device and remote control system

A remote control system comprising:

• an audio signal processing device for generating an output sound signal by alleviating a noise component in an input sound signal including both a sound component to be heard and the noise component, the audio signal processing device comprising:
• a first conversion circuit configured to convert the input sound signal into first information, the first information being frequency-domain information of the input sound signal;
• a storage device configured to store second information, the second information being frequency-domain information of a composite sound signal formed with pure tones of a plurality of frequencies extracted from a frequency band that is to be cancelled and that includes a frequency band of the noise component alleviated in the audio signal processing device;
• an adaptive filter configured to receive the second information as an input and output third information as an adapted output signal, the third information being frequency-domain information of a noise-canceling sound;
• a subtractor configured to output fourth information, the fourth information being frequency-domain information obtained by subtracting the third information from the first information;
• and
• a second conversion circuit configured to convert the fourth information into a sound signal and output the sound signal as the output sound signal,
• wherein the adaptive filter is configured to perform an adaptation operation assuming that the fourth information is an error,
• wherein said remote control system further comprises:
• a vehicle system installed in a vehicle;
• and
• a control system configured to control the vehicle remotely,
• wherein the vehicle system includes:
• a microphone configured to pick up a sound in which a sound to be heard and noise are mixed, and output a monitoring sound signal;
• and
• a transmitter configured to transmit the monitoring sound signal output from the microphone to the control system,
• wherein the control system includes:
• a receiver configured to receive the monitoring sound signal from the vehicle system;
• a speaker;
• and
• the audio signal processing device, and
• wherein the monitoring sound signal received by the receiver is input to the audio signal processing device as the input sound signal, and the output sound signal is output from the audio signal processing device to the speaker.