Individual fine tuning of single microphone noise reduction settings in hearing aids

Listening in environments with different kinds of background noises is especially difficult for individuals who suffer from hearing loss. For this reason, most modern hearing aids contain noise reduction (NR) algorithms. It is known that individual preferences for the settings of these algorithms are very diverse. Therefore, research is conducted to find NR parameters that are important for determining the preference of a listener and to find out what aspects, other than speech intelligibility, influence this preference.
An important theme in this work is the trade-off between noise attenuation and signal quality which is a delicate balance that presumably determines the success of individual fine tuning of NR settings. When removing more unwanted noise from a signal the signal quality is inevitably affected as signal distortions arise. In the first four chapters of this thesis we investigated the effect of NR on listening effort, and the effect of varying NR time constants and NR strength on listener preference. The individual trade-off was a supposed reason as to why preferences are so diverse. In the fifth chapter of this thesis we visualized this trade-off and indeed found that each individual has a different tolerance towards background noise and signal distortions.
The main aim of this thesis was to aid in the adequate and efficient selection and fine tuning of the optimal NR algorithm in a hearing aid for each individual listener. All research chapters of this work have contributed to this overarching goal.