title: Advanced beamformers for cochlear implant users: acute measurement of speech perception in challenging listening conditions.
abstract: OBJECTIVE
  To investigate the performance of monaural and binaural beamforming technology with an additional noise reduction algorithm, in cochlear implant recipients.
  
  
  METHODS
  This experimental study was conducted as a single subject repeated measures design within a large German cochlear implant centre. Twelve experienced users of an Advanced Bionics HiRes90K or CII implant with a Harmony speech processor were enrolled. The cochlear implant processor of each subject was connected to one of two bilaterally placed state-of-the-art hearing aids (Phonak Ambra) providing three alternative directional processing options: an omnidirectional setting, an adaptive monaural beamformer, and a binaural beamformer. A further noise reduction algorithm (ClearVoice) was applied to the signal on the cochlear implant processor itself. The speech signal was presented from 0° and speech shaped noise presented from loudspeakers placed at ±70°, ±135° and 180°. The Oldenburg sentence test was used to determine the signal-to-noise ratio at which subjects scored 50% correct.
  
  
  RESULTS
  Both the adaptive and binaural beamformer were significantly better than the omnidirectional condition (5.3 dB±1.2 dB and 7.1 dB±1.6 dB (p<0.001) respectively). The best score was achieved with the binaural beamformer in combination with the ClearVoice noise reduction algorithm, with a significant improvement in SRT of 7.9 dB±2.4 dB (p<0.001) over the omnidirectional alone condition.
  
  
  CONCLUSIONS
  The study showed that the binaural beamformer implemented in the Phonak Ambra hearing aid could be used in conjunction with a Harmony speech processor to produce substantial average improvements in SRT of 7.1 dB. The monaural, adaptive beamformer provided an averaged SRT improvement of 5.3 dB.
authors.affiliation: Department of Otolaryngology, Medical University Hannover, Hannover, Germany; Cluster of Excellence hearing4all, Medical University Hannover, Hannover, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Buechner
authors.affiliation: Department of Otolaryngology, Medical University Hannover, Hannover, Germany.
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Dyballa
authors.affiliation: Advanced Bionics GmbH, European Research Center, Hannover, Germany.
authors.forename: Phillipp
authors.initials: P
authors.lastname: Hehrmann
authors.affiliation: Advanced Bionics GmbH, European Research Center, Hannover, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Fredelake
authors.affiliation: Department of Otolaryngology, Medical University Hannover, Hannover, Germany; Cluster of Excellence hearing4all, Medical University Hannover, Hannover, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lenarz
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001309:Auditory Threshold; D003054:Cochlear Implants; D004777:Environment; D006801:Humans; D008875:Middle Aged; D059629:Signal-To-Noise Ratio; D013067:Speech Perception
references.citation: Ear Hear. 2005 Dec;26(6):669-79
references.pmid: 16378001
references.citation: J Acoust Soc Am. 2006 Oct;120(4):2216-27
references.pmid: 17069317
references.citation: Am J Audiol. 1999 Dec;8(2):117-27
references.pmid: 10646195
references.citation: J Acoust Soc Am. 2013 Jul;134(1):596-606
references.pmid: 23862834
references.citation: Ear Hear. 2007 Feb;28(1):62-72
references.pmid: 17204899
references.citation: J Am Acad Audiol. 2011 Feb;22(2):65-80
references.pmid: 21463562
references.citation: Otol Neurotol. 2012 Jun;33(4):553-60
references.pmid: 22588233
references.citation: Ear Hear. 2002 Feb;23(1 Suppl):49S-58S
references.pmid: 11883767
references.citation: Ear Hear. 2000 Feb;21(1):45-58
references.pmid: 10708073
references.citation: J Acoust Soc Am. 1993 Oct;94(4):1930-3
references.pmid: 8227739
references.citation: Acta Otolaryngol Suppl. 1990;469:85-90
references.pmid: 2356741
references.citation: J Acoust Soc Am. 1997 Oct;102(4):2412-21
references.pmid: 9348699
references.citation: Trends Amplif. 2006 Dec;10(4):175-200
references.pmid: 17172547
references.citation: Int J Audiol. 2005 Mar;44(3):144-56
references.pmid: 15916115
references.citation: Am J Audiol. 2012 Dec;21(2):295-312
references.pmid: 22858614
references.citation: J Acoust Soc Am. 1995 Apr;97(4):2498-503
references.pmid: 7714267
references.citation: Ear Hear. 2006 Dec;27(6):714-31
references.pmid: 17086081
references.citation: Ear Hear. 2012 Jul-Aug;33(4):e13-23
references.pmid: 22555182
references.citation: J Acoust Soc Am. 2001 Mar;109(3):1134-43
references.pmid: 11303927
references.citation: Ear Hear. 2001 Oct;22(5):420-30
references.pmid: 11605949
references.citation: Otol Neurotol. 2010 Dec;31(9):1386-90
references.pmid: 20856160
references.citation: J Acoust Soc Am. 1996 May;99(5):3138-48
references.pmid: 8642122
references.citation: Arch Otolaryngol Head Neck Surg. 2004 May;130(5):624-8
references.pmid: 15148187
references.citation: J Am Acad Audiol. 2005 Jul-Aug;16(7):473-84
references.pmid: 16295234
references.citation: Ear Hear. 2004 Aug;25(4):375-87
references.pmid: 15292777
references.citation: Am J Otol. 1997 Nov;18(6 Suppl):S46-9
references.pmid: 9391593
references.citation: Int J Audiol. 2002 Mar;41(2):100-12
references.pmid: 12212855
references.citation: J Acoust Soc Am. 1992 Mar;91(3):1662-76
references.pmid: 1564202
references.citation: J Am Acad Audiol. 2010 Jul-Aug;21(7):441-51; quiz 487-8
references.pmid: 20807480
references.citation: Trends Amplif. 2012 Jun;16(2):102-16
references.pmid: 22923425
references.citation: J Am Acad Audiol. 1999 Apr;10(4):180-9
references.pmid: 10941709