title: Two-microphone spatial filtering provides speech reception benefits for cochlear implant users in difficult acoustic environments.
abstract: This article introduces and provides an assessment of a spatial-filtering algorithm based on two closely-spaced (∼1 cm) microphones in a behind-the-ear shell. The evaluated spatial-filtering algorithm used fast (∼10 ms) temporal-spectral analysis to determine the location of incoming sounds and to enhance sounds arriving from straight ahead of the listener. Speech reception thresholds (SRTs) were measured for eight cochlear implant (CI) users using consonant and vowel materials under three processing conditions: An omni-directional response, a dipole-directional response, and the spatial-filtering algorithm. The background noise condition used three simultaneous time-reversed speech signals as interferers located at 90°, 180°, and 270°. Results indicated that the spatial-filtering algorithm can provide speech reception benefits of 5.8 to 10.7 dB SRT compared to an omni-directional response in a reverberant room with multiple noise sources. Given the observed SRT benefits, coupled with an efficient design, the proposed algorithm is promising as a CI noise-reduction solution.
authors.affiliation: Research & Development, Sensimetrics Corporation, 14 Summer Street, Suite 305, Malden, Massachusetts 02148.
authors.forename: Raymond L
authors.initials: RL
authors.lastname: Goldsworthy
authors.affiliation: Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 36-791, Cambridge, Massachusetts 02139.
authors.forename: Lorraine A
authors.initials: LA
authors.lastname: Delhorne
authors.affiliation: Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 36-791, Cambridge, Massachusetts 02139.
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Desloge
authors.affiliation: Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 36-791, Cambridge, Massachusetts 02139.
authors.forename: Louis D
authors.initials: LD
authors.lastname: Braida
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D019929:Cochlear Implantation / Q000295:instrumentation*; D003054:Cochlear Implants; D004558:Electric Stimulation; D004777:Environment; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects*; D010470:Perceptual Masking; D019986:Persons with Hearing Disabilities / Q000523:psychology / Q000534:rehabilitation*; D012815:Signal Processing, Computer-Assisted; D013067:Speech Perception; D013069:Speech Reception Threshold Test; D013997:Time Factors; D055815:Young Adult
references.citation: J Acoust Soc Am. 1995 May;97(5 Pt 1):3099-111
references.pmid: 7759650
references.citation: J Acoust Soc Am. 2012 Sep;132(3):EL250-6
references.pmid: 22979840
references.citation: J Acoust Soc Am. 1971 Feb;49(2):Suppl 2:467+
references.pmid: 5541744
references.citation: J Acoust Soc Am. 1994 Mar;95(3):1593-602
references.pmid: 8176062
references.citation: Ear Hear. 2001 Oct;22(5):420-30
references.pmid: 11605949
references.citation: J Acoust Soc Am. 1993 Sep;94(3 Pt 1):1332-42
references.pmid: 8408974
references.citation: Am J Otol. 1997 Nov;18(6 Suppl):S46-9
references.pmid: 9391593
references.citation: J Acoust Soc Am. 1999 Dec;106(6):L71-4
references.pmid: 10615713
references.citation: J Acoust Soc Am. 2013 Apr;133(4):2412-20
references.pmid: 23556606
references.citation: J Acoust Soc Am. 2008 Apr;123(4):2379-90
references.pmid: 18397040
references.citation: Ear Hear. 1992 Aug;13(4):263-71
references.pmid: 1397769
references.citation: J Acoust Soc Am. 1975 Jul;58(1):214-22
references.pmid: 1150969
references.citation: J Comp Physiol Psychol. 1948 Feb;41(1):35-9
references.pmid: 18904764
references.citation: J Acoust Soc Am. 2005 Mar;117(3 Pt 1):1001-4
references.pmid: 15806989
references.citation: J Acoust Soc Am. 1998 Oct;104(4):2372-84
references.pmid: 10491701
references.citation: J Acoust Soc Am. 2003 May;113(5):2861-73
references.pmid: 12765402
references.citation: J Commun Disord. 1989 Jun;22(3):193-207
references.pmid: 2525570
references.citation: J Acoust Soc Am. 2010 Jun;127(6):3689-95
references.pmid: 20550267
references.citation: Ear Hear. 2011 May-Jun;32(3):382-90
references.pmid: 21206365
references.citation: J Acoust Soc Am. 1995 Apr;97(4):2498-503
references.pmid: 7714267
references.citation: Ear Hear. 2012 Jul-Aug;33(4):e13-23
references.pmid: 22555182
references.citation: J Acoust Soc Am. 2006 Oct;120(4):2216-27
references.pmid: 17069317
references.citation: Nature. 2002 Mar 7;416(6876):87-90
references.pmid: 11882898
references.citation: Ear Hear. 2007 Feb;28(1):62-72
references.pmid: 17204899
references.citation: J Rehabil Res Dev. 1993;30(1):82-94
references.pmid: 8263832
references.citation: J Acoust Soc Am. 1998 Dec;104(6):3586-96
references.pmid: 9857517
references.citation: J Acoust Soc Am. 2008 Jul;124(1):498-509
references.pmid: 18646993
references.citation: Trends Amplif. 2013 Mar;17(1):27-44
references.pmid: 23429419
references.citation: Scand Audiol. 1994;23(2):105-9
references.pmid: 8085109
references.citation: J Acoust Soc Am. 2003 Feb;113(2):961-8
references.pmid: 12597189
references.citation: IEEE Trans Audio Speech Lang Process. 2011 Jul 18;20(2):599-609
references.pmid: 22207823
references.citation: J Acoust Soc Am. 1992 Mar;91(3):1662-76
references.pmid: 1564202
references.citation: Ear Hear. 1982 Mar-Apr;3(2):72-6
references.pmid: 7075872
references.citation: Ear Hear. 2011 May-Jun;32(3):323-30
references.pmid: 21187752
references.citation: Acta Otolaryngol Suppl. 2004 Mar;(551):56-9
references.pmid: 15078080
references.citation: J Rehabil Res Dev. 1993;30(1):117-28
references.pmid: 8263822
references.citation: J Speech Hear Res. 1986 Jun;29(2):275-81
references.pmid: 3724121
references.citation: Neuroreport. 2002 Sep 16;13(13):1635-9
references.pmid: 12352617
references.citation: J Acoust Soc Am. 2002 Jan;111(1 Pt 1):377-86
references.pmid: 11831811
references.citation: Hear Res. 2009 Apr;250(1-2):27-37
references.pmid: 19450437