Wide-dynamic compression algorithm of digital hearing aid under noise condition

TL;DR: In this paper, a wide-dynamic compression algorithm of a digital hearing aid in a noise environment is presented. But the algorithm does not consider the effect of the sound pressure level of an outside sound source.

Abstract: The invention provides a wide-dynamic compression algorithm of a digital hearing aid in a noise environment. The wide-dynamic compression algorithm comprises the following steps of (A) outputting a de-noised voice signal by means of a voice enhancement algorithm, (B) estimating a voice signal output feedback path, performing boundary checking calculation and performing calculation and output according to three self-adaptive wide-dynamic compression rules, (C) using an output obtained the step A and an output obtained the step B as an input of a wide-dynamic compression module to perform voice signal compression and amplification and improve signal-noise ratio. When the sound pressure level of an outside sound source is smaller than hearing threshold of a normal person according to a traditional compression algorithm, the hearing aid ordinarily does not start the compression algorithm, the output sound pressure level is set as 0, and therefore a part of information of audio signals is lost. By means of the wide-dynamic compression algorithm, the process is improved and optimized, the part of information of audio signals with the sound pressure level smaller than hearing threshold of the normal person is kept, and meanwhile a noise elimination function is provided.