Hearing aid signal processing
Launer, Stefan
Hearing aid signal processing
This chapter reviews the general types of signal processing that are used
in modern digital hearing aids. The focus is on concepts underlying the processing
rather than on details of the implementation. The signal processing can be classified
into three broad classes: (1) Processing to apply frequency- and level-dependent
amplification to restore audibility and provide acceptable loudness, based on the
hearing profile of the individual (usually the audiogram but sometimes taking into
account the results of loudness scaling) and the preferences of the individual.
Frequency lowering can be considered as an additional method for restoring the
audibility of high-frequency sounds. (2) Sound cleaning, for example, partial
removal of stationary noises or impulse sounds and reduction of acoustic feedback.
Noise reduction may be achieved using both single-microphone and multiplemicrophone
algorithms, but only the latter have been shown to improve intelligibility.
(3) Environment classification for automatically controlling the settings of a
hearing aid in different listening situations. It is concluded that modern hearing aids
can be effective in restoring audibility and providing acceptable loudness and listening
comfort, but they are still of limited effectiveness in improving the intelligibility
of speech in noisy situations.
Beamforming • Binaural beamforming • Compression speed • Directional microphone • Environment classification • Frequency compression • Frequency lowering • Multichannel compression • Noise canceler • Noise reduction • Pinna simulation • Reverberation canceler • Signal processing • Spectral change
Hearing aid signal processing
This chapter reviews the general types of signal processing that are used
in modern digital hearing aids. The focus is on concepts underlying the processing
rather than on details of the implementation. The signal processing can be classified
into three broad classes: (1) Processing to apply frequency- and level-dependent
amplification to restore audibility and provide acceptable loudness, based on the
hearing profile of the individual (usually the audiogram but sometimes taking into
account the results of loudness scaling) and the preferences of the individual.
Frequency lowering can be considered as an additional method for restoring the
audibility of high-frequency sounds. (2) Sound cleaning, for example, partial
removal of stationary noises or impulse sounds and reduction of acoustic feedback.
Noise reduction may be achieved using both single-microphone and multiplemicrophone
algorithms, but only the latter have been shown to improve intelligibility.
(3) Environment classification for automatically controlling the settings of a
hearing aid in different listening situations. It is concluded that modern hearing aids
can be effective in restoring audibility and providing acceptable loudness and listening
comfort, but they are still of limited effectiveness in improving the intelligibility
of speech in noisy situations.
Beamforming • Binaural beamforming • Compression speed • Directional microphone • Environment classification • Frequency compression • Frequency lowering • Multichannel compression • Noise canceler • Noise reduction • Pinna simulation • Reverberation canceler • Signal processing • Spectral change