Introduction:
The highly infectious Coronavirus disease (Covid-19) was first reported in December, 2019 and it spread swiftly throughout the world causing a pandemic. In India, most colleges have resorted to e-teaching modes, due to lockdown restrictions. This has led to students spending several hours with the computers/mobile phones, causing a significant increase in the use of Personal Listening Devices (PLDs).
Earlier studies have examined the use of PLDs such as cassette players, Walkman, CD players, MP3 Players, and iPods among young adults.(1-3) But currently, mobile phones have replaced all of them, because of their affordability and variety of functions. Mobile phones with large storage capacities are being used to listen to music, watch movies, make phone calls, and participate in video conferences, increasing the likelihood of users using them for much longer periods of time.
Several studies have reported of significant impact of prolonged listening with PLDs on hearing, including Temporary Threshold shifts,(4) Permanent threshold shifts,(5-7) Threshold shift at high frequencies,(8-10) and at extended High frequencies,(8,11,12) reduced amplitude of OAEs,(8,9,11) and increased prevalence of tinnitus.(5,9,11)
Hence the current study sought to determine the practices and preferences for PLD use among college students during the Covid-19 pandemic, as well as to assess their knowledge of PLD use and hearing conservation. The study's findings may aid in determining the necessity and content of awareness campaigns aimed at college students.
Material and Methods
The study was approved by the Institutional ethical committee [Reference No: IHEC-II/0154/22]. A questionnaire was developed after reviewing the earlier studies on PLDs use among college students and young adults.(3,13,14) The survey questionnaire was designed using the template provided by Google forms. The questionnaire consisted of three sections, namely (i) Demographics, (ii) Practices and Preferences for use of PLDs, (iii) Knowledge relating to use of PLDs and hearing conservation. Excluding the demographic data, the survey consisted of 21 closed set questions. There were 16 questions regarding the Practices and preferences for use of PLDs, and 5 questions assessed the knowledge regarding the use of PLDs and Hearing conservation. Due to the lack of familiarity with the term PLDs in India, the term headphone was used throughout the questionnaire. Due to variances in terminology, participants were also shown photographs of various types of transducers to help them choose the type of transducer they use. The questionnaire was validated for its content by five Audiologists and recommended changes were incorporated in the questionnaire. The Content Validity Index (CVI) score of the questionnaire was 0.82. The questionnaire also had a good test-retest reliability with Cohen's kappa ranging from 0.68 to 0.86.
As we aimed to study the practice, preferences and knowledge among the college students in India, the questionnaire was shared via social media groups of college students in India, like in the previous studies.(13,15) The link to the questionnaire was posted in social media groups of college undergraduate students in Kerala and Tamil Nadu, two southern states in India. Only students who were willing to complete the questionnaire took part in the study. As a result, the questionnaire respondents were self-selected. Informed Consent was obtained from the participants at the beginning of the survey. The survey took approximately 10 minutes to complete. A total of 899 subjects participated in the cross-sectional descriptive survey.
The obtained responses were manually verified for completeness. Responses that were incomplete were rejected. The number of responses and percentage of responses generated by Google forms for each question were used for further analysis.
Results
A total of 899 responses were received, of which five responses were removed as they were incomplete. Thus, there were a total of 894 valid responses. As, the questionnaire was shared multiple times on social media, it is not possible to determine the response rate. All the participants had responded to most questions. Except for some, where the questions were not applicable to the respondents. Furthermore, for some questions, such as devices used to attend online classes, respondents could choose more than one option, resulting in a total overall percentage greater than 100%.
Demographics of the participants
Table 1 shows the demographics of the participants. The majority of the participants were in the age range of 17-24 years (Q1: 97.5%), with very few participants in the age range of 25- 32years (Q1: 2.5%). There were more females (Q2: 66.1%) when compared to males (Q2: 33.9%). The students were from various specialties such as Medicine, Allied Health Sciences, Engineering, Technology, Science, and Arts, and they came from all years of the programme, from the first to the final year. As the survey was shared multiple times, the survey had a wide reach and we were able to sample the students from a number of different universities. Though there were participants from across the country, most students belonged to the southern states of India, especially, Tamil Nadu and Kerala.
| Table 1: Demographics of the participants in the survey |
| S.No. |
Question |
Response |
Number |
Percentage |
1. |
Age (n=894) |
17-20 |
529 |
59.2 |
21-24 |
343 |
38.3 |
25-32 |
22 |
2.5 |
2. |
Gender (n=894) |
Male |
303 |
33.9 |
Female |
591 |
66.1 |
Practices and preferences for online classes
Table 2 shows the practices and preferences for online classes (Q3-7). The vast majority of the participants (Q3: 95.9%) reported to attend online classes. Three-fourth of them reported to attend online classes for 2-6 hrs/day (Q4: 74.2%). Half of the participants (Q5: 55.1%) reported to attend online classes for 3 hrs or more continuously each day. More than one third (Q6: 36.2%) of the participants reported to attend classes in noisy to very noisy environment. The majority of the participants (Q7: 91.9%) reported to use mobile phones to attend online classes, followed by laptops and very few reported to use desktop computers and tablets.
| Table 2: Practices and preferences for online classes |
| S.No. |
Question |
Response |
Number |
Percentage |
3. |
Do you currently attend online classes? (n=894) |
Yes |
857 |
95.9 |
No |
37 |
4.1 |
4. |
If yes, for how long each day? (n=857) |
1-2 hrs |
161 |
18.8 |
2-4 hrs |
294 |
34.3 |
4-6 hrs |
342 |
39.9 |
>6 hrs |
60 |
7 |
5. |
For how long do you attend classes continuously every day? (n=857) |
1hr |
187 |
21.8 |
2 hrs |
198 |
23.1 |
3 hrs |
170 |
19.9 |
>3 hrs |
302 |
35.2 |
6. |
What is the level of background noise when you attend online classes (n=857) |
Very Quiet |
78 |
9.1 |
Quiet |
469 |
54.7 |
Noisy |
281 |
32.8 |
Very Noisy |
29 |
3.4 |
7. |
Which device do you use to attend online classes? (n=857) |
Mobile Phones |
788 |
91.9 |
Desktop computers |
15 |
1.8 |
Laptop |
193 |
22.5 |
Tablets |
15 |
1.8 |
Duration of PLD use
Table 3 shows the number and percentage of responses to questions regarding the duration of PLD use (Q: 8-12). More than, three -fourth (Q8: 84.8%) of the participants reported to use transducers such as wired earbuds along with mobile phones/laptops while attending online classes. Among them, more than one fourth of the participants on an average used it for more than 4 hrs/day (Q9: 29.8%), and more than half of the participants (Q9: 59.2%) used it for 1-4 hrs/day. Similar to online classes, the majority of the participants (Q10: 91.8%) used transducers for leisure. The majority of participants stated that they use it to listen to music, followed by watching movies and playing games. More than one fourth (Q12:36.2%) of the participants used PLDs for more than 2 hrs /day for leisure activities.
| Table 3: Duration of PLD use |
| S. No. |
Question |
Response |
Number |
Percentage |
8. |
Do you use headphones for your online classes? (n= 857) |
No |
130 |
15.2 |
Yes |
727 |
84.8 |
9. |
If yes, For how long each day? (n=727) |
Less than 1 hr |
80 |
11 |
1-2 hrs |
149 |
20.5 |
2-3 hrs |
141 |
19.4 |
3-4 hrs |
140 |
19.3 |
>4 hr |
217 |
29.8 |
10. |
Do you use your headphones for leisure? (n=894) |
No |
73 |
8.2 |
Yes |
821 |
91.8 |
11. |
If yes, Specify(n=821) |
Watch Movies |
440 |
53.6 |
Listen to Music |
600 |
73.1 |
Play Games |
165 |
20.1 |
Others |
146 |
17.8 |
12. |
For how long do you use headphones for leisure each day? (n=894) |
Never |
73 |
8.2 |
Less than 1 hr |
254 |
28.4 |
1-2 hrs |
243 |
27.2 |
2-3 hrs |
135 |
15.1 |
3-4 hrs |
95 |
10.6 |
>4 hrs |
94 |
10.5 |
PLD users Practice, Preference and Symptoms
Table 4 displays the number and percentage of responses to questions about Practice, Preference and Symptoms of PLD users (Q13-18). Because of superior audibility, less background noise, privacy, and comfort, three-quarters of the participants (Q 13: 73%) chose PLDs to speakers for their classes. The majority of the participants (Q15: 79.6%) used the wired earbuds that were supplied along with mobile phones followed by Bluetooth earphones (Q15: 15.9%), ear pods, supra-aural headphones, noise cancelling headphones, and gaming headphones. The majority of the participants listened at levels of less than 80% of the maximum volume and, 12.8% (Q16) listened at exceedingly high volumes. More than one third (Q17: 34.7%) of the participants reported a very high screen time of >6 hrs/day. A large number of the participants reported of ear irritation (Q18: 34.2%), ear pain (Q18:30.2%), accumulation of earwax (Q18: 20.4%) followed by difficulty listening in noise (Q18: 11.9%), tinnitus (Q18: 8.2%), and worsened hearing (Q18: 8.1%).
| Table 4: PLD users Practice, Preference and symptoms |
| S.No. |
Question |
Response |
Number |
Percentage |
13. |
Which of the audio output do you prefer for your classes? (n=894) |
Headphones |
653 |
73.0 |
Speakers |
241 |
27.0 |
14. |
If Headphones, why?
(n=653) |
Comfort |
194 |
29.7 |
Reduced background Noise |
374 |
57.3 |
Better Audibility |
469 |
71.8 |
Privacy |
236 |
36.1 |
15. |
Which type of headphone do you use? (n=894) |
Wired headphones |
712 |
79.6 |
Bluetooth earphones |
143 |
15.9 |
Ear Pod |
63 |
7.0 |
Gaming Headphone |
10 |
1.1 |
Supra-aural Headphones |
56 |
6.3 |
Noise cancelling headphones |
34 |
3.8 |
16. |
When using headphones, what is your typical volume setting? (n=894) |
0-25% of the maximum volume |
109 |
12.2 |
26-50% of the maximum volume |
325 |
36.3 |
51-80% of the maximum volume |
346 |
38.7 |
81-100% of the maximum volume |
114 |
12.8 |
17. |
What is your total screen time per day? (n=894) |
Less than 1 hr |
38 |
4.3 |
1-2 hrs |
76 |
8.5 |
2-4 hrs |
188 |
21 |
4-6 hrs |
282 |
31.5 |
>6hrs |
310 |
34.7 |
18. |
Do you experience any of the following symptoms? (n=894) |
Ear Pain |
270 |
30.2 |
Ear irritation |
306 |
34.2 |
Tinnitus |
73 |
8.2 |
Worsened Hearing |
72 |
8.1 |
Difficulty listening in noise |
106 |
11.9 |
Accumulation of ear wax |
182 |
20.4 |
Headache |
32 |
3.6 |
Knowledge regarding the use of PLD and hearing conservation
Table 5 depicts the number and percentage of responses to questions regarding the knowledge of use of PLD and hearing conservation (Q19-23). The majority (Q19:73.8%) were aware that excessive use of PLDs may cause hearing problems, and half the participants (Q20: 50.1%) reported that the use of PLDs should be limited to less than an hour a day. Three-fourth of the participants (Q 21: 78.1%) felt the safe listening volume as less than 50% of the maximum volume. But unfortunately, the majority reported wired earbuds (Q 23: 41.4%) to be the safest, followed by noise cancelling headphones (Q: 35.6%), Bluetooth earphones and ear pods.
| Table 5: Knowledge regarding Hearing conservation |
| S.No. |
Question |
Response |
Numbers |
Percentage |
19. |
Can excessive use of headphone cause hearing problems? (n=894) |
Yes |
660 |
73.8 |
No |
74 |
8.3 |
Not sure |
160 |
17.9 |
20. |
How long can a person be permitted to listen to headphones in a day? (n=894) |
Less than 30 mins |
131 |
14.6 |
30 mins-1 hr |
317 |
35.5 |
1-2 hrs |
280 |
31.3 |
2-4 hrs |
134 |
15 |
4-6 hrs |
32 |
3.6 |
21. |
What is the safe volume setting while using headphones? (n=894) |
0-25 % of the maximum volume |
196 |
21.9 |
26-50% of the maximum volume |
502 |
56.2 |
51-80% of the maximum volume |
181 |
20.2 |
81-100 % of the maximum volume |
15 |
1.7 |
22. |
Have you ever had a hearing test? (n=894) |
Yes |
211 |
23.6 |
No |
683 |
76.4 |
23. |
Which type of headphone is the safest? (n=894) |
Wired earphones |
370 |
41.4 |
Ear pods |
98 |
10.9 |
Blue tooth earphones |
108 |
12.1 |
Noise cancelling headphones |
318 |
35.6 |
Discussion
Compared to the other age groups, college students have higher needs and opportunities for increased use of PLDs. Hence the current study was focused particularly among the college students.
Duration of use of PLDs
In the current study, majority of the participants reported to use PLDs for less than 2 hrs a day for leisure. The duration is similar to that reported by Hoover and Krishnamurthi who have reported that the majority of the participants (76.5%) used PLDs for 2 hrs or less.(14)
In addition to using the PLDs for leisure, the participants also reported to use it for online classes. More than half of the participants used it for 1-4 hrs/day and more than quarter of them for greater than 4 hrs a day.
Considering the average duration each day, which would be the sum of listening for online classes and listening for leisure, some of the participants could be listening for close to 6 hrs /day or more. This is very concerning, as the use of PLDs for prolonged periods, have been reported to be associated with increased hearing thresholds. For e.g., Hutchinson et al.(16) reported that participants exceeding use of PLDs by 7.5 hrs/week had increased hearing thresholds. Similar increase in hearing threshold with exposure exceeding 7hrs/week has also been reported by Meyer-Bisch,(7) and Buffe et al.(17) The additional risk of continuous listening for several hours without adequate breaks could be very concerning.
Transducer Types
Many participants preferred to use PLDs, as versus speakers, as it provided better audibility, and more privacy. Zogby,(18) have also reported young teens preferring PLDs due to its advantage to listen to music at loud levels without disturbing others.
The majority of the participants in the current study used the wired ear buds that were supplied along with the mobile phones, followed by Bluetooth earphones. And only few participants reported to use over-the-ear headphones, and noise cancelling headphones. Similarly, Hutchinson et al. in their study among college students, reported that the majority of the participants used the ear buds and only very few students used the noise cancelling headphones.(16) Similar results have also been reported in other studies.(13-15)
The main disadvantage of wired earbuds is that they do not provide adequate attenuation, which may lead to the user increasing the volume in the presence of background noise, which may in turn affect the user’s hearing. Fligor and Cox,(1) Hodgetts et al.,(2) have reported that, the iPod stock earbuds do not provide adequate attenuation of background noise, causing the user to increase the volume on their iPod. The preferred listening levels (PLL) have been found to be higher with ear buds, especially in the presence of the background noise.(2)
Listening Volume
One third of the participants in the current study listened at loud levels of 51-80 %, and 12% listened at a very loud levels of 81-100 % of the maximum volume. Similar to the current study about 35 % listened at loud levels,(3) and a quarter of the participants exceeded 85 dB(A).(19) Portnuff et al., had also reported that younger people listen at higher volumes.(20)
Portnuff et al reported that 75-84% of the maximum volume corresponded to 89.4 dB(A), whereas 85-94% of the maximum volume corresponded to 95.6 dB(A).(20) Similarly, Torre (2008) reported that the perception of loud and very loud sounds corresponded to 88 and 98 dBSPL when the participants listened with their PLDs.(3) This is alarming as these levels exceed the permissible noise levels, and can be harmful if used for prolonged duration.
Levels of Background Noise
The level of the background noise is important, as the user may increase the volume levels when the background noise is high. In the current survey, more than a third of the participants reported to attend classes in noisy and very noisy environments. Similarly, Danhauer et al.,(13) in the survey among college students reported that one third of their participants were frequently in noisy environment. And they in turn increased their volumes when in noisy situation (78.2%). Hodgetts, et al.,(2) had also reported that the participants’ listening levels were between 75-78dB in a quiet environment, but increased by 6-10 dB in the presence of background noise.
Adults rarely exceeded the daily dose of 100 % when listening in a quiet environment. In the presence of high background noise (61-80 dBA), however, 27.4 % of the subjects exceed the daily dose.(21) Because the majority of the participants also reported using standard ear buds included with their smart phones, which have poor background noise reduction, there is an even larger chance of increasing the volume.
Symptoms experienced by the participants
In the current study, ear pain and ear irritation were the most common symptoms reported by the participants. Similar to the present findings, Hoover and Krishnamurthi(14) and Sulaiman et al.,(11) reported that greater than one third of the participants reported ear soreness following the use of earphones. This could be attributed to the quality of the ear buds, which are supplied with the mobile phones.
Only 8% of the participants reported of worsened hearing, and Tinnitus. Similarly, results have also been reported by Danhauer et al.,(13) and Torre(3) for hearing loss (10-11%) and tinnitus (15.9%). Despite the fact that only a small percentage of individuals experienced hearing loss, they may show preclinical symptoms that can be detected with OAEs and extended high frequency audiometry.(16,22) As a result, students must be educated about the numerous signs and symptoms of hearing loss, as well as the importance of getting an audiological evaluation on a regular basis. Because the effects of noise exposure are cumulative,(5) and the NIHL develops over time, it's critical to educate the young adults about the long-term consequences.
Knowledge of PLD use
The responses were encouraging as the majority of the participants were aware that prolonged use of PLDs could cause hearing difficulties, and that the safe listening volume was less than half of the maximum volume, and the daily PLD use should be limited to one hour. Similarly, Muchnik et al.,(23) and You et al.,(15) had reported that majority of the participants knew that listening at high intensity levels was related to hearing loss. But the participants in the current study reported wired PLDs (Earbuds) to be the safest.
Several of the earlier studies point out that most PLD users use it at safe listening levels and for limited time, thus limiting the effects on hearing.(18) But in the current survey, the majority of the participants were listening at loud to very loud listening levels, continuously for 2-3 or more hrs and for a total of 2-6 hrs /day, also in the presence of background noise, posing a great risk to their hearing. Given the combination of all of these elements, as well as continued use over the last year and a half, the effects on hearing is extremely concerning.
Hence it is important to educate the young college students on hearing conservation in order to prevent hearing loss. Firstly, the students must be educated to reduce the back ground noise levels, as they may increase the loudness levels in the presence of noise. Reducing the background noise, can partly help prevent exceeding the 100 % daily noise exposure.(21) Secondly, listening with stock ear buds should be discouraged since listening levels were substantially higher;(2) instead, insert earphones/noise cancelling headphones should be strongly advised because they can help attenuate background noise better than stock ear buds.(20,24) Thirdly, they must be encouraged to attend to lectures using speakers whenever possible.
The number of educational resources available on the use of PLDs is minimal. Although there is organised information for school-aged children (the Dangerous Decibel programme),(25) there is no similar programme for adolescents and adults, who are at a higher risk. Hence age appropriate, educational material must be made available. With the target audience being young adults, social media might be utilised to spread awareness using experts in the field to develop safe listening habits. It's also important to create awareness about the role of the audiologist.
Clear information on the permissible duration and permissible level of listening via PLDs and the use of a safe listening device would be beneficial, as the majority of young adults were willing to reduce their listening levels if they were unsafe.(16) Through the use of volume limiting software, users may also be notified when they exceed the permissible limitations in their smart phones.(26)
Some of the limitations of the study include, the sample population. Though the subjects were from all parts of India, majority were from the southern states. Because participation was voluntary, those who were concerned about hearing may have taken part in the survey. Furthermore, the participants' self-perception of the loudness levels at which they used the PLD was used rather than the direct measurement of the output levels from the users' PLDs. Although previous research has shown that users can provide an accurate self-report of the intensity with which they use their device.
Conclusion
The use of PLDs for both leisure and for listening to online classes increases the overall listening duration. Furthermore, continuous listening for several hours per day and over a long period of time, particularly with stock earbuds, may contribute to NIHL. Though it is difficult to predict the exact number of participants at risk, the riskiest among the respondents may be those who listen for more than 6 hours per day, at high volume, for 4 hours or more continuously, and in noisy environments. Thus, an educational programme aimed at college students that focuses on hearing conservation in order to prevent NIHL is essential. It is also the individual's responsibility to use PLDs at safe listening levels for safe durations with adequate break times.
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