Is it valid to calculate the 3-kilohertz threshold by averaging 2 and 4 kilohertz?

Otolaryngol Head Neck Surg. 2012 Jul;147(1):102-4. doi: 10.1177/0194599812437156. Epub 2012 Feb 2.

Abstract

Many guidelines for reporting hearing results use the threshold at 3 kilohertz (kHz), a frequency not measured routinely. This study assessed the validity of estimating the missing 3-kHz threshold by averaging the measured thresholds at 2 and 4 kHz. The estimated threshold was compared to the measured threshold at 3 kHz individually and when used in the pure-tone average (PTA) of 0.5, 1, 2, and 3 kHz in audiometric data from 2170 patients. The difference between the estimated and measured thresholds for 3 kHz was within ± 5 dB in 72% of audiograms, ± 10 dB in 91%, and within ± 20 dB in 99% (correlation coefficient r = 0.965). The difference between the PTA threshold using the estimated threshold compared with using the measured threshold at 3 kHz was within ± 5 dB in 99% of audiograms (r = 0.997). The estimated threshold accurately approximates the measured threshold at 3 kHz, especially when incorporated into the PTA.

MeSH terms

  • Audiometry, Pure-Tone / methods*
  • Audiometry, Pure-Tone / statistics & numerical data
  • Auditory Threshold*
  • Diagnostic Errors
  • Humans
  • Mathematics
  • Reproducibility of Results