title: [Correlation of pure tone thresholds and hearing loss for numbers. Comparison of three calculation variations for plausibility checking in expertise].
abstract: BACKGROUND
  The present study analyzes the best combination of frequencies for the calculation of mean hearing loss in pure tone threshold audiometry for correlation with hearing loss for numbers in speech audiometry, since the literature describes different calculation variations for plausibility checking in expertise. Three calculation variations, A (250, 500 and 1000 Hz), B (500 and 1000 Hz) and C (500, 1000 and 2000 Hz), were compared.
  
  
  METHODS
  Audiograms in 80 patients with normal hearing, 106 patients with hearing loss and 135 expertise patients were analyzed in a retrospective manner. Differences between mean pure tone audiometry thresholds and hearing loss for numbers were calculated and statistically compared separately for the right and the left ear in the three patient collectives.
  
  
  RESULTS
  We found the calculation variation A to be the best combination of frequencies, since it yielded the smallest standard deviations while being statistically different to calculation variations B and C. The 1- and 2.58-fold standard deviation (representing 68.3% and 99.0% of all values) was ±4.6 and ±11.8 dB for calculation variation A in patients with hearing loss, respectively.
  
  
  CONCLUSIONS
  For plausibility checking in expertise, the mean threshold from the frequencies 250, 500 and 1000 Hz should be compared to the hearing loss for numbers. The common recommendation reported by the literature to doubt plausibility when the difference of these values exceeds ±5 dB is too strict as shown by this study.
authors: Klinik und Poliklinik für Hals-Nasen-Ohrenheilkunde, Ludwig-Maximilians-Universität München, Marchioninistr. 15, 81377, München, Deutschland. thomas.braun@med.uni-muenchen.de
authors: T
authors: T
authors: Braun
authors: S
authors: S
authors: Dochtermann
authors: E
authors: E
authors: Krause
authors: M
authors: M
authors: Schmidt
authors: K
authors: K
authors: Schorn
authors: J M
authors: JM
authors: Hempel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data*; D001302:Audiometry, Speech / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data*; D001309:Auditory Threshold; D002648:Child; D005104:Expert Testimony / Q000331:legislation & jurisprudence*; D005260:Female; D006316:Hearing Loss, High-Frequency / Q000175:diagnosis*; D006319:Hearing Loss, Sensorineural / Q000145:classification / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013223:Statistics as Topic; D055815:Young Adult