title: Working memory capacity may influence perceived effort during aided speech recognition in noise.
abstract: BACKGROUND
  Recently there has been interest in using subjective ratings as a measure of perceived effort during speech recognition in noise. Perceived effort may be an indicator of cognitive load. Thus, subjective effort ratings during speech recognition in noise may covary both with signal-to-noise ratio (SNR) and individual cognitive capacity.
  
  
  OBJECTIVE
  The present study investigated the relation between subjective ratings of the effort involved in listening to speech in noise, speech recognition performance, and individual working memory (WM) capacity in hearing impaired hearing aid users.
  
  
  METHODS
  In two experiments, participants with hearing loss rated perceived effort during aided speech perception in noise. Noise type and SNR were manipulated in both experiments, and in the second experiment hearing aid compression release settings were also manipulated. Speech recognition performance was measured along with WM capacity.
  
  
  METHODS
  There were 46 participants in all with bilateral mild to moderate sloping hearing loss. In Experiment 1 there were 16 native Danish speakers (eight women and eight men) with a mean age of 63.5 yr (SD = 12.1) and average pure tone (PT) threshold of 47. 6 dB (SD = 9.8). In Experiment 2 there were 30 native Swedish speakers (19 women and 11 men) with a mean age of 70 yr (SD = 7.8) and average PT threshold of 45.8 dB (SD = 6.6).
  
  
  METHODS
  A visual analog scale (VAS) was used for effort rating in both experiments. In Experiment 1, effort was rated at individually adapted SNRs while in Experiment 2 it was rated at fixed SNRs. Speech recognition in noise performance was measured using adaptive procedures in both experiments with Dantale II sentences in Experiment 1 and Hagerman sentences in Experiment 2. WM capacity was measured using a letter-monitoring task in Experiment 1 and the reading span task in Experiment 2.
  
  
  RESULTS
  In both experiments, there was a strong and significant relation between rated effort and SNR that was independent of individual WM capacity, whereas the relation between rated effort and noise type seemed to be influenced by individual WM capacity. Experiment 2 showed that hearing aid compression setting influenced rated effort.
  
  
  CONCLUSIONS
  Subjective ratings of the effort involved in speech recognition in noise reflect SNRs, and individual cognitive capacity seems to influence relative rating of noise type.
authors.affiliation: Swedish Institute for Disability Research, Linköping University, Sweden.
authors.forename: Mary
authors.initials: M
authors.lastname: Rudner
authors.forename: Thomas
authors.initials: T
authors.lastname: Lunner
authors.forename: Thomas
authors.initials: T
authors.lastname: Behrens
authors.forename: Elisabet Sundewall
authors.initials: ES
authors.lastname: Thorén
authors.forename: Jerker
authors.initials: J
authors.lastname: Rönnberg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001301:Audiometry, Pure-Tone; D003071:Cognition / Q000502:physiology*; D005260:Female; D006310:Hearing Aids; D034381:Hearing Loss / Q000175:diagnosis / Q000503:physiopathology* / Q000534:rehabilitation; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D009622:Noise; D013067:Speech Perception / Q000502:physiology*