Abstract: The present disclosure provides a computer-implemented method for sound masking. The method includes identifying one class among a plurality of classes based on frequency characteristics of a voice of a first occupant in a vehicle, obtaining reference voice data corresponding to the identified class, generating a personalized masking sound for the first occupant by synthesizing the reference voice data with white noise, and controlling an output of the personalized masking sound.

Abstract: A method of selectively performing signal processing in a first mode and in a second mode. In the first mode, a noise cancel signal having a signal characteristic to cancel an external noise component is generated based on a voice signal supplied from a microphone, and an input digital audio signal and the noise cancel signal are combined into a voice signal to be output through a speaker. In the second mode, a sound process for vocal voice is performed on a voice signal supplied from a microphone, a vocal voice component is canceled from a digital audio signal of input music to generate a karaoke signal, and the karaoke signal and the vocal signal are combined into a voice signal to be output through a speaker. The first mode corresponds to an audio replay operation accompanied by noise cancel, and the second mode corresponds to a karaoke operation.