BACKGROUND: Loudness Discomfort Level (LDL), a test used in the hearing aid fitting process, has alsobeen recommended to evaluate patients with tinnitus and/or suspect of hyperacusis. AIM: to determineLDL reference values for normal hearing individuals and to correlate the LDL to the Acoustic ReflexThreshold (ART). METHOD: LDL was investigated in 64 normal hearing subjects, with ages between 18and 25 years (53.1% female), in the frequency threshold of 0.5 to 8KHz and for speech (non-recorded,non-standardized connected discourse). Pulsate pure tones were presented for two seconds, with a one-second interval between each presentation. The initial stimulus intensity was at 50dB and was followedby ascending presentations, of 5dB each, until the subject referred initial discomfort with loudness. Thetesting procedure was performed separately in each ear, and was immediately repeated at the end of thetest (test and retest situation). The choice of the ear that would start the testing procedure wasalternated for each subject. After that contralateral acoustic reflexes ART were measured. The presenceof the ART was indicated by a minimal needle deflection (larger than 0.05ml) on the emittanceequipment. RESULTS: median varied from 86 to 98dBHL, with no statistically significant differencesbetween gender (p > 0.11), between ears (p > 0.36) and between the test-retest situation (p > 0.34). Thedetermination coefficients (r²) of the linear regression model revealed absence of correlation betweenlog(LDL) and log(ART). CONCLUSION: normal hearing individuals have LDL between 86 and 98dBHLfor all of the tested stimuli. Inter-subject differences and the good reproductivity suggest that theinterpretation of the test should be cautious and analyzed considering the patient’s history. The testcan be an useful instrument go follow-up patients. No correlation was found between LDL and ART.
Loudness Perception; Hearing; Hyperacusis; Tinnitus
