• Madhumati Shridhar Kuntoji
• Dr. Kiran V ,

In humans, Sensory Neural Hearing Loss (SNHL) leads to decreased frequency selectivity [1] leading to poor speech perception. This is a most common hearing problem in humans across the world. It is not much known about effect of SNHL on frequency selectivity which is function of speech signal level [1]. Auditory filter frequency response is approximately linear in hearing impaired people but it is nonlinear in normal hearing people. Therefore frequency discrimination ability is very poor in hearing impaired people. This type of hearing problem becomes severe in noisy situations. Speech noise reduction is very much essential for hearing impaired people using hearing aids. Here a low computational intense, noise reduction technique, suitable for hearing aids is presented. Most of the noise reduction algorithms process magnitude of Fourier Transform (FT) of speech signal but phase is kept as it is [3]. In contrast here magnitude of FT of noisy speech signal is kept unprocessed and phase alone is processed. Processed spectrum of speech is obtained by combining unprocessed magnitude spectrum and processed phase spectrum [3]. Phase spectrum processing (modification) is based on the type of noise and signal to noise ratio of speech corrupted by noise. This method of processing results in reduction of low energy components (generally noise) more as compared to high-energy (generally speech) components. Reduction of noise is very much required in hearing aids along with other signal processing operations. Laboratory evaluation of noise corrupted speech and experimentally modified speech samples reveal that present technique is able to reduce noise and improve speech quality. Noise reduction is attained by phase alteration of Fourier transform of input noisy speech signal using imaginary parts of FT.

Noise reduction, Hearing problems, Hearing aids, STFT, Magnitude spectrum, Phase spectrum, Symmetry of FT.

"Speech Noise Reduction in Hearing Aids to Improve Perceptual Quality of Speech Using Discrete Fourier Transform ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.8, Issue 8, page no.e570-e575, August-2021, Available :http://www.jetir.org/papers/JETIR2108556.pdf

"Speech Noise Reduction in Hearing Aids to Improve Perceptual Quality of Speech Using Discrete Fourier Transform ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.8, Issue 8, page no. ppe570-e575, August-2021, Available at : http://www.jetir.org/papers/JETIR2108556.pdf