Test-retest reliability of loudness scaling.
OBJECTIVE
Establish the test-retest reliability of loudness scaling using a bounded category rating method.


METHODS
The individual loudness functions were investigated in three groups of listeners: seven normal-hearing listeners age 18 to 35 yr, five normal-hearing listeners aged 57 to 84 yr, and five listeners aged 54 to 82 yr with bilateral sloping sensorineural hearing loss. Test-retest reliability was investigated by determining the intralistener, between-session standard deviation.


RESULTS
The pattern of test-retest reliability was similar across all three groups. It improved as the intensity of the stimulus increased: 7 dB at the first quartile of the loudness function, and 3 dB at the third quartile. Two to four runs of the task appear to be sufficient to obtain a stable loudness function, and it was shown that an exponential function provided a better goodness of fit than a linear function (r2: 0.99 compared with 0.94).


CONCLUSIONS
Loudness scaling is a longer test than most conventional suprathreshold measures and requires special equipment. However, it has good test-retest reliability and provides more information on the loudness function that might be useful in the fitting of nonlinear hearing aids. The data show that an exponential function provides a good fit to the loudness growth data, and should probably be incorporated into fitting algorithms associated with loudness scaling.
Robinson
K
K
MRC Institute of Hearing Research, Royal Infirmary, Glasgow, Scotland.
Gatehouse
S
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D006309:Hearing / Q000502:physiology; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis; D006801:Humans; D008144:Loudness Perception; D015203:Reproducibility of Results