title: Clinical evaluation of a new hearing aid anti-cardioid directivity pattern.
abstract: OBJECTIVE
  The purpose of this research was to evaluate a new directional hearing aid algorithm which automatically adapts to an anti-cardioid pattern in background noise when a speech signal originates from behind the hearing aid user.
  
  
  METHODS
  Using the hearing-in-noise-test (HINT) in the soundfield, with the sentences delivered adaptively from the back (180°) and the standard HINT competing noise from the front (0°; 72 dB SPL), the participants were tested for three different hearing aid conditions: omnidirectional, conventional adaptive directional, and adaptive directional with the anti-cardioid algorithm enabled.
  
  
  METHODS
  Adults (n = 21) with bilaterally symmetrical downward sloping sensorineural hearing loss; experienced hearing aid users and aided bilaterally for experimental testing.
  
  
  RESULTS
  Results revealed a significant effect for the hearing aid microphone setting (p < .0001), with a HINT mean RTS of 4.2 dB for conventional adaptive directional, -0.1 dB for omnidirectional, and -5.7 dB when the anti-cardioid algorithm was active. This was a large effect size (Cohen's f2).
  
  
  CONCLUSIONS
  The findings suggest that the signal classification system steered the algorithm correctly, and that when implemented, the anti-cardioid polar pattern resulted in an improvement in speech recognition in background noise for this listening situation.
authors.affiliation: Department of Hearing and Speech Sciences, Vanderbilt University, Nashville, USA. gus@gusmueller.net
authors.forename: H Gustav
authors.initials: HG
authors.lastname: Mueller
authors.forename: Jennifer
authors.initials: J
authors.lastname: Weber
authors.forename: Martina
authors.initials: M
authors.lastname: Bellanova
mesh_terms: D000161:Acoustic Stimulation; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D012048:Correction of Hearing Impairment / Q000523:psychology; D005260:Female; D006310:Hearing Aids; D006319:Hearing Loss, Sensorineural / Q000523:psychology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects; D010470:Perceptual Masking; D019986:Persons with Hearing Disabilities / Q000523:psychology / Q000534:rehabilitation*; D011571:Psychoacoustics; D021641:Recognition, Psychology; D012815:Signal Processing, Computer-Assisted; D013067:Speech Perception; D013069:Speech Reception Threshold Test