A real-time hearing-aid research platform (HARP): realization, calibration, and evaluation

In current hearing aid (HA) research and development a real-time HA platform is often required to perform highly controlled manipulations of the considered signal processing as well as the signal presentation to the listener's ears. Although a large number of possible hardware and software solutions have been described in the relevant literature, very few studies exist that provide a coherent description of all the concepts, techniques and strategies that are involved in realizing an entire HA platform. The present study therefore provides a detailed description of all the methods that were applied for one example HA platform realization. The descriptions include: (i) the required hardware and software to realize and calibrate the HA platform, (ii) the equalization and calibration of the applied hardware from the sound signals picked up by the HA microphones to the signals at the ears of an individual listener, (iii) the implementation of an example multi-channel wide dynamic-range compressor that can be directly applied in HA research, (iv) the fitting to a given hearing loss, and (v) the evaluation of the temporal and spectral behaviour of the example compressor.