RESULTS:
A total of 246 students participated in the study. However, only 221 satisfied the inclusion criteria. We excluded rest as exclusion criteria. Mean age of students was 21 years (S.D: ±0.927; Range: 20-24). Out of 221, 74.7% (n=165) were females while 25.3% (n=56) were males. Students from 3rd year and 4th year were almost equal (49.3% Vs. 50.7% respectively). Among recruited sample, 96.4% (n=213) were regularly using electroacoustic devices. With insert type earphones being the most common (73.8%; n=163). Followed by Bluetooth handsfree (14%; n=31) and supra-aural headphones (5%; n=11). Students reported smartphone (90%; n=199) as the most frequently used source for listening to these devices, followed by laptop (32.6%; n=72) and tablet (5.9%; n=13).
Listening duration of 44.8% (n=99) medical students stood between one to two hours per 24 hours. Nevertheless, 19.5% (n=43) exceeded three hours per day. In our study, 26.2% (n=58) undergraduates practiced high volume setting for listening. Near half of the users (47.9%; n=106) were experiencing electroacoustic devices beyond five years. Wherein 22.6% (n=24) were enjoying their use for 10 or more years.
We found statistically significant difference among average listening duration between male (165.77 ± 103.39 minutes) and female students (120.09 ± 121.76 minutes) t (219) = 2.516, p =0.013. We did not observe any significant difference for volume setting (p=0.851) and duration since years (p=0.145) with gender. Likewise, no statistically significant difference existed between volume setting preference (p=0.977) and duration since years (p=0.820) with year of study. TABLE I represents the listening habits of our study sample.
Among electroacoustic device users Rinne test was negative (BC >AC) in 3 ears on right side. Weber test was lateralized in 7% (n=15) to right ear and same for the left ear. Almost one third of medical students who were using electroacoustic devices suffered mild sensorineural hearing loss (SNHL) at frequencies 250 Hz (31.9%; n=68) and 500 Hz (31.5%; n=67) in right ear. In left ear, 29.1% (n=62) at frequency of 250 Hz while 23% (n=49) at 500 Hz fall under mild SNHL. In our study only 5.6% (n=12) and 6.6% (n=14) students suffered mild (sensorineural) hearing loss at 4kHz and 8kHz in right ear, respectively. There was no air bone gap in any of the cases. TABLE II summarizes the hearing thresholds of electroacoustic device users at audiometric octave frequencies.
We applied Pearson correlation to find association of hearing loss with per day listening duration and listening years. We did not find any significant correlation with per day duration. However, we noticed statistically significant association between listening years and hearing loss. Positive correlation existed at 500Hz (p=<.001), 1000Hz (p=<.001), 2000Hz (p=<.001) in right ear. In left ear, there was significant positive correlation at 250Hz (p=<.001), 500Hz (p=<.001), 1000Hz (p=0.04) and 2000Hz (p=<.001).
Independent t test carried at 95% CI did not show any significant difference between mean hearing thresholds of male and female students. TABLE III displays the means at octave frequencies among male and female students.