A digital hearing aid is provided that includes front and rear microphones, a
sound
processor, and a speaker. Embodiments of the digital hearing aid include an occlusion
subsystem, and a directional processor and headroom expander. The front microphone
receives a front microphone acoustical signal and generates a front microphone
analog signal. The rear microphone receives a rear microphone acoustical signal
and generates a rear microphone analog signal. The front and rear microphone analog
signals are converted into the digital domain, and at least the front microphone
signal is coupled to the sound processor. The sound processor selectively modifies
the signal characteristics and generates a processed signal. The processed signal
is coupled to the speaker which converts the signal to an acoustical hearing aid
output signal that is directed into the ear canal of the digital hearing aid user.
The occlusion sub-system compensates for the amplification of the digital hearing
aid user's own voice within the ear canal. The directional processor and headroom
expander optimizes the gain applied to the acoustical signals received by the digital
hearing aid and combine the amplified signals into a directionally-sensitive response.