Test-retest reliability of distortion-product thresholds compared to behavioral auditory thresholds
Katharina Bader1, Linda Dierkes1, Lore Helene Braun2
1Department of Otolaryngology, Head and Neck Surgery, Eberhard-Karls-University Tübingen, Elfriede-Aulhorn-Straße 5, 72076 Tübingen, Germany.
Hearing Research
|May 13, 2021
Summary
This study found that estimated distortion-product thresholds derived from level maps (EDPTLM) offer reliable, objective monitoring of cochlear health. This method shows improved test-retest reliability compared to previous techniques, potentially enabling earlier detection of cochlear damage.
Area of Science:
- Auditory Neuroscience
- Otoacoustic Emissions
- Hearing Threshold Measurement
Background:
- Serial monitoring of pure-tone behavioral thresholds and distortion-product otoacoustic emissions (DPOAEs) aids in detecting cochlear damage progression.
- Estimated distortion-product thresholds (EDPTs) from DPOAE input-output functions offer quantitative hearing loss estimates but are limited by wave interference and stimulus level choices.
- Accurate and reliable methods are needed for objective monitoring of cochlear function, especially for conditions like ototoxicity.
Purpose of the Study:
- To evaluate the test-retest reliability of EDPTs derived from short-pulse DPOAE level maps (EDPTLM).
- To compare the reliability of EDPTLM against EDPTs from semi-logarithmic functions (EDPTI/O) and behavioral audiometry (PTA, TA).
- To establish EDPTLM as a sensitive method for objectively monitoring cochlear status and potentially refining clinical indicators for follow-up examinations.
Main Methods:
- Recorded DPOAE-based auditory thresholds (EDPTLM, EDPTI/O) and behavioral thresholds (PTA, TA) seven times over three months in 20 ears of 10 normal-hearing subjects.
- Utilized short-pulse DPOAEs with 21 L1,L2 pairs to derive EDPTLM via nonlinear curve fitting of DPOAE growth behavior.
- Assessed test-retest reliability using centered thresholds, average threshold differences, and average absolute threshold differences across all frequencies (1-14 kHz).
Main Results:
- No significant differences in test-retest reliability were found between EDPTLM, EDPTI/O, PTA, and TA when using centered thresholds or average threshold differences.
- Average absolute threshold differences showed small but significant variations: PTA (3.00 dB), TA (3.20 dB), EDPTLM (3.34 dB), and EDPTI/O (3.51 dB).
- EDPTLM demonstrated the highest test-retest reliability at higher frequencies (11-14 kHz), while TA was most reliable at lower frequencies (1-2 kHz).
Conclusions:
- The test-retest reliability of EDPTLM is superior to EDPTI/O and comparable to behavioral thresholds, making it a promising objective method for cochlear monitoring.
- EDPTLM effectively circumvents limitations of previous EDPT methods, offering a sensitive approach to assess cochlear amplifier function.
- Detecting a 5 dB equidirectional threshold shift in both EDPTLM and TA could serve as a stricter indicator for follow-up, beneficial for monitoring conditions like ototoxicity.
