Test-retest reliability of loudness scaling

Area of Science:

• Audiology
• Psychoacoustics
• Hearing Science

Background:

• Loudness scaling is a psychoacoustic method to quantify perceived sound intensity.
• Understanding the reliability of loudness scaling is crucial for its clinical application.
• Conventional suprathreshold measures may not fully capture loudness perception.

Purpose of the Study:

• To establish the test-retest reliability of loudness scaling using a bounded category rating method.
• To investigate loudness functions in normal-hearing and hearing-impaired listeners.
• To determine the optimal fitting function for loudness growth data.

Main Methods:

• Investigated loudness functions in three listener groups: young normal-hearing, older normal-hearing, and older hearing-impaired.
• Assessed test-retest reliability via intralistener, between-session standard deviation.
• Compared goodness of fit for linear and exponential functions.

Main Results:

• Test-retest reliability was consistent across all groups and improved with stimulus intensity.
• Reliability was 7 dB at the first quartile and 3 dB at the third quartile of the loudness function.
• An exponential function (r2: 0.99) provided a better fit than a linear function (r2: 0.94).

Conclusions:

• Loudness scaling exhibits good test-retest reliability, despite being a lengthy procedure.
• The exponential function offers a superior fit for loudness growth data.
• Findings support incorporating loudness scaling and exponential function fitting into nonlinear hearing aid fitting algorithms.