title: Behavioral and neural discrimination of speech sounds after moderate or intense noise exposure in rats.
abstract: OBJECTIVE
  Hearing loss is a commonly experienced disability in a variety of populations including veterans and the elderly and can often cause significant impairment in the ability to understand spoken language. In this study, we tested the hypothesis that neural and behavioral responses to speech will be differentially impaired in an animal model after two forms of hearing loss.
  
  
  METHODS
  Sixteen female Sprague-Dawley rats were exposed to one of two types of broadband noise which was either moderate or intense. In nine of these rats, auditory cortex recordings were taken 4 weeks after noise exposure (NE). The other seven were pretrained on a speech sound discrimination task prior to NE and were then tested on the same task after hearing loss.
  
  
  RESULTS
  Following intense NE, rats had few neural responses to speech stimuli. These rats were able to detect speech sounds but were no longer able to discriminate between speech sounds. Following moderate NE, rats had reorganized cortical maps and altered neural responses to speech stimuli but were still able to accurately discriminate between similar speech sounds during behavioral testing.
  
  
  CONCLUSIONS
  These results suggest that rats are able to adjust to the neural changes after moderate NE and discriminate speech sounds, but they are not able to recover behavioral abilities after intense NE. Animal models could help clarify the adaptive and pathological neural changes that contribute to speech processing in hearing-impaired populations and could be used to test potential behavioral and pharmacological therapies.
authors: 1School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, Texas, USA; and 2MGH Institute of Health Professions, Boston, Massachusetts, USA.
authors: Amanda C
authors: AC
authors: Reed
authors: Tracy M
authors: TM
authors: Centanni
authors: Michael S
authors: MS
authors: Borland
authors: Chanel J
authors: CJ
authors: Matney
authors: Crystal T
authors: CT
authors: Engineer
authors: Michael P
authors: MP
authors: Kilgard
mesh_terms: D000818:Animals; D001303:Auditory Cortex / Q000503:physiopathology*; D001304:Auditory Diseases, Central / Q000209:etiology* / Q000503:physiopathology; D001522:Behavior, Animal; D004192:Discrimination, Psychological; D005260:Female; D006317:Hearing Loss, Noise-Induced / Q000503:physiopathology*; D009622:Noise / Q000009:adverse effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013067:Speech Perception / Q000502:physiology*