title: Hearing-aid users' voices: a factor that could affect directional benefit.
abstract: OBJECTIVE
  Backward-facing directional processing (Back-DIR) is an algorithm that employs an anti-cardioid directivity pattern to enhance speech arriving from behind the listener. An experiment that was originally designed to evaluate Back-DIR, together with its follow-up experiment, are reported to illustrate how hearing-aid users' voices could affect directional benefit.
  
  
  METHODS
  Speech recognition performance was measured in a speech-180°/noise-0° configuration, with aids programmed to Back-DIR enabled or omnidirectional processing. In the original experiment, the conventional hearing-in-noise test (HINT) was used, wherein listeners repeated heard sentences. In the follow-up experiment, a modified HINT was used, wherein a carrier phrase was presented before each sentence.
  
  
  METHODS
  Fifteen adults with sensorineural hearing loss participated in both experiments.
  
  
  RESULTS
  Significant Back-DIR benefit (relative to omnidirectional processing) was observed in the follow-up experiment, while not in the original experiment.
  
  
  CONCLUSIONS
  In the original experiment, hearing aids were affected by listeners' voices such that Back-DIR was not always activated when the target speech was presented. In the follow-up experiment, listeners' voice effects were eliminated by the carrier phrase activating Back-DIR before the sentences were presented. The results suggest that the effect of hearing-aid technologies is highly dependent on the characteristics of listening conditions.
authors.affiliation: Department of Communication Sciences and Disorders, The University of Iowa , Iowa City , USA.
authors.forename: Yu-Hsiang
authors.initials: YH
authors.lastname: Wu
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Stangl
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Bentler
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001302:Audiometry, Speech; D012048:Correction of Hearing Impairment / Q000295:instrumentation*; D005260:Female; D006310:Hearing Aids; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000503:physiopathology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects; D010470:Perceptual Masking; D019986:Persons with Hearing Disabilities / Q000534:rehabilitation*; D021641:Recognition, Psychology; D012815:Signal Processing, Computer-Assisted; D013017:Sound Localization; D013067:Speech Perception; D014833:Voice Quality