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.