The usage of personal listening devices (PLDs) is associated with risks of hearing loss. The aim of this study is to evaluate the effects of music exposure from these devices on high-frequency hearing thresholds of PLD users.
INTRODUCTION: The present study aimed to obtain preliminary tympanometric data of young Malay adults and to compare the results between genders.
METHODS: 96 undergraduate students (49 males and 47 females), aged 19-25 (mean and standard deviation 21.14 +/- 1.31) years, participated in this study. Otoscopic examination, pure tone audiometry, qualitative tympanogram and ipsilateral acoustic reflex were measured to ensure a clear ear canal, normal hearing and normal middle ear function, prior to tympanometric measurement. As a result, a total of 154 ears (80 ears from males and 74 ears from females) were selected for further statistical analyses. The tympanometric parameters measured were peak compensated static acoustic admittance (Peak Y(tm)), tympanometric width (TW) and equivalent ear canal volume (V(ea)).
RESULTS: The results showed that the mean Peak Y(tm), V(ea) and TW for males were 0.81 mmhos, 1.48 cubic cm and 113.67 daPa, respectively. The mean Peak Y(tm), V(ea) and TW for females were 0.63 mmhos, 1.12 cubic cm and 98.04 daPa, respectively. Males were found to have significantly higher mean V(ea) and mean Peak Y(tm) than females. However no significant gender difference was observed in the mean TW.
CONCLUSION: The current study suggests that young Malay adults may require gender-specific Peak Y(tm) and V(ea) values when implementing a quantitative approach in tympanogram interpretation.
Schroeder-phase masking complexes have been used in many psychophysical experiments to examine the phase curvature of cochlear filtering at characteristic frequencies, and other aspects of cochlear nonlinearity. In a normal nonlinear cochlea, changing the "scalar factor" of the Schroeder-phase masker from -1 through 0 to +1 results in a marked difference in the measured masked thresholds, whereas this difference is reduced in ears with damaged outer hair cells. Despite the valuable information it may give, one disadvantage of the Schroeder-phase masking procedure is the length of the test - using the conventional three-alternative forced-choice technique to measure a masking function takes around 45 min for one combination of probe frequency and intensity. As an alternative, we have developed a fast method of recording these functions which uses a Békésy tracking procedure. Testing at 500 Hz in normal hearing participants, we demonstrate that our fast method: i) shows good agreement with the conventional method; ii) shows high test-retest reliability; and iii) shortens the testing time to 8 min.
The higher field strength magnetic resonance imaging (MRI) such as 3 Tesla (T) and above generates noise that has potential detrimental effects on the hearing. Temporary threshold shifts following MRI examination have been reported for MRI with lower field strength. Such effect, however, have not been reported so far for a 3T MRI. We report a case that exemplifies the possible detrimental effects of a 3 T MRI generated noise on the auditory system. Our patient underwent investigation of his chronic backache in a 3 T MRI unit and developed hearing loss and tinnitus post-MRI examination. Hearing assessment was done using pure tone audiogram, distortion product otoacoustic emission (DPOAE) and brainstem electrical response audiometry (BERA) which revealed a unilateral sensorineural hearing loss which recovered within 3 days. However the tinnitus persisted. This is possibly a case of temporary threshold shift following noise exposure. However a sudden sensorineural hearing loss remains the other possibility.