title: Evaluation of a spectral subtraction strategy to suppress reverberant energy in cochlear implant devices.
abstract: The smearing effects of room reverberation can significantly impair the ability of cochlear implant (CI) listeners to understand speech. To ameliorate the effects of reverberation, current dereverberation algorithms focus on recovering the direct sound from the reverberated signal by inverse filtering the reverberation process. This contribution describes and evaluates a spectral subtraction (SS) strategy capable of suppressing late reflections. Late reflections are the most detrimental to speech intelligibility by CI listeners as reverberation increases. By tackling only the late part of reflections, it is shown that users of CI devices can benefit from the proposed strategy even in highly reverberant rooms. The proposed strategy is also compared against an ideal reverberant (binary) masking approach. Speech intelligibility results indicate that the proposed SS solution is able to suppress additive reverberant energy to a degree comparable to that achieved by an ideal binary mask. The added advantage is that the SS strategy proposed in this work can allow for a potentially real-time implementation in clinical CI processors.
authors.affiliation: Department of Speech-Language-Hearing, University of Kansas, 1000 Sunnyside Avenue, Lawrence, Kansas 66045, USA.
authors.forename: Kostas
authors.initials: K
authors.lastname: Kokkinakis
authors.affiliation: Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, 9200 West Wisconsin Avenue, Milwaukee, Wisconsin 53226, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Runge
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Wisconsin-Milwaukee, 3200 North Cramer Street, Milwaukee, Wisconsin 53211, USA.
authors.forename: Qudsia
authors.initials: Q
authors.lastname: Tahmina
authors.affiliation: Department of Electrical Engineering and Computer Science, University of Wisconsin-Milwaukee, 3200 North Cramer Street, Milwaukee, Wisconsin 53211, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Hu
mesh_terms: D000161:Acoustic Stimulation; D000162:Acoustics; D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D003054:Cochlear Implants; D005160:Facility Design and Construction; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000503:physiopathology / Q000523:psychology / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010470:Perceptual Masking; D010700:Phonetics; D013016:Sound; D013065:Speech Intelligibility; D013067:Speech Perception; D013382:Subtraction Technique; D058067:Wavelet Analysis; D055815:Young Adult