title: Speech recognition in noise using bilateral open-fit hearing aids: the limited benefit of directional microphones and noise reduction.
abstract: OBJECTIVE
  To investigate speech recognition performance in noise with bilateral open-fit hearing aids and as reference also with closed earmolds, in omnidirectional mode, directional mode, and directional mode in conjunction with noise reduction.
  
  
  METHODS
  A within-subject design with repeated measures across conditions was used. Speech recognition thresholds in noise were obtained for the different conditions.
  
  
  METHODS
  Twenty adults without prior experience with hearing aids. All had symmetric sensorineural mild hearing loss in the lower frequencies and moderate to severe hearing loss in the higher frequencies.
  
  
  RESULTS
  Speech recognition performance in noise was not significantly better with an omnidirectional microphone compared to unaided, whereas performance was significantly better with a directional microphone (1.6 dB with open fitting and 4.4 dB with closed earmold) compared to unaided. With open fitting, no significant additional advantage was obtained by combining the directional microphone with a noise reduction algorithm, but with closed earmolds a significant additional advantage of 0.8 dB was obtained.
  
  
  CONCLUSIONS
  The significant, though limited, advantage of directional microphones and the absence of additional significant improvement by a noise reduction algorithm should be considered when fitting open-fit hearing aids.
authors.affiliation: Department of Audiology, Sahlgrenska University Hospital, Gothenburg, Sweden. lennart.magnusson@neuro.gu.se
authors.forename: Lennart
authors.initials: L
authors.lastname: Magnusson
authors.forename: Ann
authors.initials: A
authors.lastname: Claesson
authors.forename: Maria
authors.initials: M
authors.lastname: Persson
authors.forename: Tomas
authors.initials: T
authors.lastname: Tengstrand
mesh_terms: D000161:Acoustic Stimulation; D000465:Algorithms; D001302:Audiometry, Speech; D001309:Auditory Threshold; D012048:Correction of Hearing Impairment / Q000523:psychology*; D004867:Equipment Design; D005260:Female; D006310:Hearing Aids; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000523:psychology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects / Q000517:prevention & control*; D017060:Patient Satisfaction; D010470:Perceptual Masking; D019986:Persons with Hearing Disabilities / Q000523:psychology / Q000534:rehabilitation*; D021641:Recognition, Psychology; D012720:Severity of Illness Index; D012815:Signal Processing, Computer-Assisted; D013017:Sound Localization; D013067:Speech Perception; D011795:Surveys and Questionnaires; D013997:Time Factors