A demonstration of improved precision of word recognition scores

J Speech Lang Hear Res. 2014 Apr 1;57(2):543-55. doi: 10.1044/2014_JSLHR-H-13-0017.

Abstract

PURPOSE The purpose of this study was to demonstrate improved precision of word recognition scores (WRSs) by increasing list length and analyzing phonemic errors. METHOD Pure-tone thresholds (frequencies between 0.25 and 8.0 kHz) and WRSs were measured in 3 levels of speech-shaped noise (50, 52, and 54 dB HL) for 24 listeners with normal hearing. WRSs were obtained for half-lists and full lists of Northwestern University Test No. 6 (Tillman & Carhart, 1966) words presented at 48 dB HL. A resampling procedure was used to derive dimensionless effect sizes for identifying a change in hearing using the data. This allowed the direct comparison of the magnitude of shifts in WRS (%) and in the average pure-tone threshold (dB), which provided a context for interpreting the WRS. RESULTS WRSs based on a 50-word list analyzed by the percentage of correct phonemes were significantly more sensitive for identifying a change in hearing than the WRSs based on 25-word lists analyzed by percentage of correct words. CONCLUSION Increasing the number of items that contribute to a WRS significantly increased the test's ability to identify a change in hearing. Clinical and research applications could potentially benefit from a more precise word recognition test, the only basic audiologic measure that estimates directly the distortion component of hearing loss and its effect on communication.

MeSH terms

  • Adolescent
  • Adult
  • Audiometry, Pure-Tone
  • Computer Simulation
  • Female
  • Hearing Loss, Sensorineural / diagnosis*
  • Humans
  • Linguistics
  • Male
  • Middle Aged
  • Models, Biological*
  • Noise
  • Phonetics*
  • Speech Discrimination Tests*
  • Speech Perception*
  • Speech Reception Threshold Test
  • Young Adult