Test-retest variability in testing hearing of speech

The repeatability of W-22 PB tests at levels of speech reception threshold (SRT) plus 5 to 30 dB in quiet and in white noise at S/N = 0 and 7 dB at a level of SRT plus 20 dB for 28 subjects with sensorineural hypoacusis. Standard deviations at various levels were from 9 to 13% compared to a standard deviation of less than 8% at SRT plus 40 dB. The lower variability at SRT plus 40 dB permits satisfactory confidence in the average of two measurements. However, it was found that more tests are required for the same confidence at the lower sensation levels. A protocol is suggested for carrying out this requirement.