Reproducibility of Hearing Threshold MeasurementsSupplementary Data on Bone-conduction and Speech Audiometry

Abstract

The reproducibility of bone-conduction pure-tone audiometry and speech recognition thresholds has been tested in groups of normal-hearing subjects. Each person was tested twice during the same day, and the test-retest difference was calculated. The reproducibility is presented as the standard deviation of this difference. Bone-conduction threshold measurements have a high degree of test-retest precision, whereas air-bone gaps show a large range of distribution in these normal-hearing subjects. This makes the interpretation of such gaps spurious when values are below 20-30 dB. Speech recognition threshold has the highest degree of test-retest precision of all audiometric tests, and this is probably due to the steep slope of the psychometric function at 50% intelligibility. A more detailed graphic presentation of the 50% point of intersection will bring the reproducibility down to less than 2.5 dB.

Validity of diagnostic pure-tone audiometry without a sound-treated environment in older adults

“…The average absolute difference in bone-conduction thresholds recorded in the natural and audiometric booth (3.4 ± 4.3 dB) was within previously reported bone-conduction test-retest differences (Laukli & Fjermedal, 1990;Margolis et al 2010;Swanepoel & Biagio, 2011). The average absolute test-retest variability for this same audiometer previously reported in a small group of 10 normal-hearing subjects was 7.1 ± 6.4 dB.…”

“…The average absolute test-retest variability for this same audiometer previously reported in a small group of 10 normal-hearing subjects was 7.1 ± 6.4 dB. Laukli and Fjermedal (1990) reported bone-conduction test-retest standard deviation variability between 3.2 and 4.8 dB across 250 to 4000 Hz in a small sample of normal-hearing adults. Similarly, Margolis et al (2010) reported an average absolute test-retest difference for bone-conduction thresholds of 4.1 ± 3.8 dB across frequencies.…”

Clinical validation of the AMTAS automated audiometer

“…However, in general the variation is not significantly different to reports by others. Only at 250Hz is the variation significantly greater than that reported by Laukli (Laukli & Fjermedal, 1990). In two cases the variation is significantly less than that reported by Swanepoel (2011) for manual operation of the KUDUWave audiometer at 2000Hz and overall.…”

“…To calculate the difference, the manual threshold was subtracted from the AMTAS threshold (Margolis et al, 2007). For the test-retest analysis, to conform to the method of analysis used by other studies, only data from two tests were included in the analysis rather than all three (Frank & Ragland, 1987;Laukli & Fjermedal, 1990;Margolis, Glasberg et al, 2010;Swanepoel, Mngemane et al, 2010;Swanepoel & Biagio, 2011). The results from the second and third set of thresholds were used, thereby minimising the possible learning effect resulting from the first session of automated audiometry.…”

Transcranial Attenuation of Bone-Conducted Sound When Stimulation Is at the Mastoid and at the Bone Conduction Hearing Aid Position

“…Because the thresholds with stimulation at the 4 different positions are done in consecutive order, the uncertainty can be viewed as a test-retest with the transducer disconnected between measurements. Test-retest data were not obtained in the current sample, but in a previous investigation using a masking procedure, the standard deviation for BC threshold test-retest were between 3.2 and 4.8 dB in the frequency range of 0.25 to 4 kHz (21). In that study, the 2 test situations were during the same day and not consecutive as here, and the masking sound was used while the subjects here were unilaterally deaf and did not need masking.…”