Distortion product otoacoustic emission fine-structure: An insight into the ear asymmetries

Abstract

is independent of age. Sharma and Sinha [7] studied 98 participants of different age groups and they reported a significant difference in the DPOAE fine-structure between the younger and the older age group.Currently, DPOAE is being utilized as an important measure for predicting hearing thresholds. Relationship between DPOAE amplitude levels and hearing thresholds has been reported in the past. Some authors [8][9][10] have documented a good agreement between low DPOAE levels and high auditory thresholds. This was true in a few of their subjects while in other subjects this relationship was not that good. Gaskill and Context: Use of distortion product otoacoustic emission (DPOAE) as a measure of hearing sensitivity is common in clinical practice. However, use of a more informative DPOAE fine-structure has been limited due to non-reliability of DPOAE fine-structure. Aim: The current study was aimed at testing the interaural differences between the DPOAE fine-structure across three age groups. Settings and Design: Acoustically treated room with a calibrated dual channel audiometer (Orbiter 922) along with TDH-39 headphones and B-71 bone vibrator. GSI Tympstar was used for tympanometry and acoustic reflex measurements while 'ILO V6' OAE analyzer was used for recording of DPOAE and DPOAE fine-structure. Material and Methods: A total of 98 subjects with normal peripheral hearing sensitivity were tested for DPOAE fine-structure. The three age groups consisted of young (8-18 years; n = 50), middle aged (30-40 years; n = 30), and elderly (50-60 years; n = 18). DPOAE fine-structure was studied at 8 points per octave on a total of 25 frequencies from 1000 to 8000 Hz. Statistical Analysis Used: Repeated measure analysis of variance. Results: There was a significant difference (P < 0.05) in the amplitudes at frequencies between 2000 and 3000 Hz. This was evident irrespective of the age groups. There was also a decrease in DPOAE amplitude in elderly group. Conclusions: Interaural asymmetry can be attributed as a reason to these findings and it occurred mostly in the speech perception frequencies. Reduced amplitude of DPAOE in the elderly group can be attributed to presbycusis. AbstrActAccess this article online Quick Response Code:Website: www.indianjotol.org

A comparative study on effects of diabetes on auditory functions as measured by BERA and DPOAE

“…However in age group more than 50 years, mean SNR values were comparable for two groups, reflecting a possible combined effect of aging and diabetes. 12 Similar results were seen on comparing DPOAE amplitude. However, the present study failed to detect change in DPOAE SNR and DPOAE amplitude (Ldp) value, when compared on basis of duration of diabetes.…”