Investigation of Cochlea Response Based Signal Processing

Abstract

An efficiency of cochlea has a significant contribution in a quality of human hearing and in a language development of newborn. The efficiency of cochlea clinically measured using Distortion Product Otoacoustic Emission (DPOAE). The measurement mainly restricted by acoustic interferences that disrupt response estimation. The disrupted estimation gives rise to repetition in measurement for many times or probably inaccurate efficiency assessment. In this study, investigation of cochlea response estimation was considered based on signal processing (SP), which was regarded as preliminary step toward interference reduction. An in-vivo measurement was performed on a left ear of 36 years old female with normal hearing, where cochlea stimulation and response recording was conducted using personal computer sound card in conjunction of sensitive probe system of ER-10C. The response signals were recorded and then analyzed off-line using SP of Fast Fourier Transform (FFT) and Band Pass-Finite Impulse Response (BP-FIR) filter. Results show that DPOAE frequency components can be extracted using proposed SP method at interference-free situation, where BP-FIR parameters of bandwidth 50Hz-200Hz and order 32-2048 have to be adjusted based on stimulation parameters. The findings dedicate useful investigated parameters for real-time implementation, and for further SP development at interference situation.