Open Access
ARTICLE
Research on Nonlinear Frequency Compression Method of Hearing Aid with Adaptive Compression Ratio
Xia Wang1, Hongming Shen1, Huawei Tao2, Ruiyu Liang3, Xing Deng4,5, Haijian Shao5, Li Zhao6,*, Cairong Zou6
1 School of Information Science and Technology, Nantong University, Nantong, 226019, China.
2 School of Information Science and Engineering, Henan University of Technology, Zhengzhou, 450001, China.
3 School of Communication Engineering, Nanjing Institute of Technology, Nanjing, 211167, China.
4 School of Automation, Key Laboratory of Measurement and Control for CSE, Ministry of Education, Southeast University, Nanjing, 210096, China.
5 School of Computer Science, Jiangsu University of Science and Technology, Zhenjiang, 212003, China.
6 School of Information Science and Engineering, Southeast University, Nanjing, 210096, China.
* Corresponding Author: Li Zhao. Email: .
Computer Modeling in Engineering & Sciences 2019, 121(2), 551-567. https://doi.org/10.32604/cmes.2019.06314
Abstract
To make full use of the residual audible frequency band of hearing-loss
patients and improve the intelligibility of speech, an adaptive nonlinear frequency
compression (NFC) algorithm is proposed, which amplifies signals below the cutoff
frequency while compresses signals above the cutoff frequency. Firstly, high-frequency
signals are decomposed to critical band signals according to the BARK scale. Secondly,
the global compression ratio is determined according to the patient's cutoff frequency and
maximum audible frequency. Thirdly, the sub-band compression ratio is adaptively
determined based on the global compression ratio and normalized average energy of subband
signals. Finally, the high frequency signals are transposed to low frequency bands
by compression mapping, and the phases are adjusted to the same as the original low
frequency signals. Experimental results of speech intelligibility with nine subjects
demonstrate that compared to conventional amplitude amplification and nonlinear
frequency compression algorithms the proposed algorithm significantly improves the
intelligibility of initials and sentences, while not affects the intelligibility of finals and
tones significantly.
Keywords
Cite This Article
Wang, X., Shen, H., Tao, H., Liang, R., Deng, X. et al. (2019). Research on Nonlinear Frequency Compression Method of Hearing Aid with Adaptive Compression Ratio.
CMES-Computer Modeling in Engineering & Sciences, 121(2), 551–567.