title: Prevalence of clinical referrals having hearing thresholds within normal limits.
abstract: OBJECTIVE
  To document the prevalence of clinically normal air conduction thresholds (0.5-4 kHz, bilaterally, ≤20 dB HL) among children and adults in a large audiology service and to estimate the prevalence of auditory processing disorder (APD).
  
  
  METHODS
  Over a period of one year, clinicians implemented their usual protocol and recorded a brief history for those with normal audiometry.
  
  
  METHODS
  The number of people seen by the service was 2924 children (0-16 years old) and 4757 adults (17-100 years old).
  
  
  RESULTS
  Adults and school-age children were most commonly referred by their primary care doctor for difficulties listening in noise or following a conversation, and younger children by their home health visitor for speech production problems. Children tended to be referred on to speech pathology or APD clinics whereas adults were discharged.
  
  
  CONCLUSIONS
  The prevalence of normal cases was 5.1% among the children and 0.9% among all adults. For younger adults (17-60 years, n = 1025), the prevalence was 4.0%. Based on comparison with those referred with hearing loss, we estimate the prevalence of APD among children and adults, defined as listening problems despite normal audiometry, to be about 0.5-1.0% of the general population.
authors.affiliation: Medical Research Council Institute of Hearing Research, Nottingham, UK.
authors.forename: Sally E
authors.initials: SE
authors.lastname: Hind
authors.forename: Rachel
authors.initials: R
authors.lastname: Haines-Bazrafshan
authors.forename: Claire L
authors.initials: CL
authors.lastname: Benton
authors.forename: Will
authors.initials: W
authors.lastname: Brassington
authors.forename: Beverley
authors.initials: B
authors.lastname: Towle
authors.forename: David R
authors.initials: DR
authors.lastname: Moore
mesh_terms: D000158:Acoustic Impedance Tests; D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001301:Audiometry, Pure-Tone; D001308:Auditory Perceptual Disorders / Q000175:diagnosis / Q000453:epidemiology*; D001309:Auditory Threshold; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012017:Referral and Consultation / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult