Validation of Frequency Warping (Freping) as a new tool for feedback control in hearing aids

Acoustic feedback control in hearing aids continues to be a challenging problem due to the emerging form factors in advanced hearing aids and hearables. In this work we describe the use of frequency warping, termed “Freping”, for feedback reduction in hearing aids. Freping is a discrete signal transformation which breaks feedback conditions by introducing nonlinear frequency shift in the hearing aid processing chain. The capabilities of Freping were tested in the real world on an acoustic KEMAR mannequin outfitted with a real-time hearing aid, and evaluations were carried out using Verifit, a standard verification toolbox for hearing aids. Experimental results thus far show that Freping provides additional Added Stable Gain (up to 11 dB) in current test conditions. Experiments also show that Freping successfully suppresses feedback for a representative set of mild to severe hearing loss profiles.