tailieunhanh - Báo cáo hóa học: " Research Article Synthetic Stimuli for the Steady-State Verification of Modulation-Based Noise Reduction Systems"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Synthetic Stimuli for the Steady-State Verification of Modulation-Based Noise Reduction Systems | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2009 Article ID 876371 8 pages doi 2009 876371 Research Article Synthetic Stimuli for the Steady-State Verification of Modulation-Based Noise Reduction Systems Jesko G. Lamm EURASIP Member Anna K. Berg and Christian G. Gluck Bernafon AG Morgenstrasse 131 3018 Bern Switzerland Correspondence should be addressed to Jesko G. Lamm Received 28 November 2008 Accepted 12 March 2009 Recommended by Heinz G. Goeckler Hearing instrument verification involves measuring the performance of noise reduction systems. Synthetic stimuli are proposed as test signals because they can be tailored to the parameter space of the noise reduction system under test. The article presents stimuli targeted at steady-state measurements in modulation-based noise reduction systems. It shows possible applications of these stimuli and measurement results obtained with an exemplary hearing instrument. Copyright 2009 Jesko G. Lamm et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. Introduction Noise reduction systems provide users of hearing instruments with increased listening comfort 1 . The aim of such systems is to suppress uncomfortable sounds on the one hand but to preserve speech on the other hand. Among various available noise reduction methods modulationbased processing is a common one 2 . Modulation-based noise reduction systems apply different amounts of attenuation in different frequency ranges depending on the likelihood of speech presence in each of them. Based on the observation that speech has a characteristic modulation spectrum 3 such systems measure modulation which is the fluctuation of the signal s envelope over time. The measurements treat modulation in different subbands separately such that .