Patent ID: 8170247

Claim:
A hearing aid, comprising: a microphone configured to acquire sound and generate a corresponding microphone-input signal; an external input terminal configured to acquire an inputted audio signal from an external device and generate a corresponding external-input signal; a hearing aid processor configured to receive the microphone-input signal from the microphone and the external-input signal from the external input terminal, subject the microphone-input signal to hearing aid processing to produce a microphone hearing aid signal, and subject the external-input signal to hearing aid processing to produce an external-input hearing aid signal; a facial movement detector configured to detect movement of the user's face and to generate a movement detection signal; an environmental sound detector configured to detect an amount of correlation between the microphone-input signal and the external-input signal and to generate, based on the detected amount of correlation, an environmental sound presence signal which indicates whether or not environmental sound is present in addition to sound represented in the external-input signal; and a mix ratio determination unit configured to determine a mix ratio of the microphone hearing aid signal and the external-input hearing aid signal based on the environmental sound presence signal and the movement detection signal; a mixer configured to mix the microphone hearing aid signal and the external-input hearing aid signal based on the mix ratio signal to generate a processed signal; and a receiver configured to receive and output the processed signal.