Introduction

Ear is a very sensitive organ composed of external, middle, and internal parts. All these parts could be harmed by the earphones. Noise could affect the middle and inner ear, while wax accumulation and infections could harm the external ear. Earphones have become increasingly popular, especially among teenagers. Their usage is constantly increasing worldwide. Using them for a long time may accumulate moisture and earwax and hence provide a suitable environment for bacterial and fungal growth. The presence of bacteria on the skin is normal and vital to human health, but some can cause serious ear canal infections. Furthermore, the growth of bacteria in huge numbers may lead to otitis media. According to the Centers for Disease Control and Prevention CDC, loud volume and noise for a long time might be harmful, leading to temporary or permanent hearing loss1. An impairment in hearing caused by prolonged exposure to loud sounds is known as noise-induced hearing loss (NIHL)2.

The usage of mobile phones, music devices, and gaming devices is increasing. E-learning has also become more popular these past few years. All that has led to an increase in the use of earphones globally, including Saudi Arabia. A literature review has shown the impact of noise on hearing in the different decades. In the past, the source of noise was loud musical activities and parties. In the recent studies, the main source of noise has become personal audio devices2. A recent questionnaire-based study demonstrated the public awareness of side effects and the behavior of using earphones in Saudi Arabia. It shows that the most frequent symptoms among earphone users were itching, ear pain, excessive earwax, and ringing in the ear3. A previous study with 30 earphone samples collected for bacterial culture found that Staphylococcus aureus was found in 60% of the samples4. Most people share their earphones with friends and family without knowing the contamination risk. An observational study conducted in Taif City, Saudi Arabia, among 435 participants found that most of them are using earphones (92.7%) and have ear problems (51%)5. Similar results were also reported in Libya6 and India7. Several studies have shown significant positive correlation between audio device usage and NIHL2.

The signs of having a build-up of earwax include impaired hearing, ringing, itchiness, pain, and a feeling of fullness in the ear. There’s a relationship between earphones and hearing loss. A previous study in Sweden among 60 young people showed that 60% of them use hearing devices with sound levels above 85 Decibel (dB), which might lead to hearing loss8. In addition, two hours of hearing sounds around 80–85 dB might damage the hearing process9. An older study has shown that the use of audio devices is increasing among students7. They are even used more nowadays as online teaching has become more popular. A recent study in Saudi Arabia reported that over 50% of the 1086 participants are exposed to noise when using their earphones and are not aware of the causes of hearing loss10. Since we have seen a rise in the usage of earphones nowadays, we hypothesized that complication rates would be high in this population. We carried out this multidisciplinary study to assess the auditory, infectious, and dermatologic complications in earphone users. The secondary objective aimed to assess earphone users’ awareness and to link their attitudes with the complications found in the study.

Methodology

Study design and participants

A cross-sectional study was conducted between August 2023 and February 2024 in Qassim region, Saudi Arabia. The target population is earphone users who are older than 17 and willing to participate in the study. Inclusion criteria include people who live in Qassim, Saudi Arabia, 17 years old or above, and use earphones. Exclusion criteria involve all participants who do not use earphones.

Informed consent

Once each participant was fully informed of the objectives and methods of the study, they were asked to sign an informed consent. It was signed by one of the parents for the two participants who were 17 years old. The information gathered was kept confidential and used solely for the study.

Sample size calculation

The sample size estimation for a cross-sectional study with one group is calculated using the formula: n = N × P (1 − P) \ [(N − 1) d ^2\z ^2] + p (1 − P). Here, N represents the population size (57), P is the estimated proportion (0.5) for the proportion of individuals using earphones, d is the desired precision (0.05), and z = 1.96. Plugging in the values, we get n = 57 × 0.5 (1 − 0.5) \ (57 − 1) (0.05^2\1.96^2) + 0.5 (1 − 0.5), which simplifies to n = 14.25 \ [(56) (6.507 × 10^ − 4( ] + 0.25. Further simplification yields n = 14.25 \ 0.286, resulting in n = 49.7. Therefore, the estimated number of research participants is approximately 50 who use earphones.

Sample collection methods

After collecting data from the participants, a sample was collected from their earphones. The samples were collected in the college laboratory. After following safety standards, the participants’ earphones were gathered and taken one by one. Cotton swabs were dipped in normal saline for seconds so that we could take as much as possible from the earphones. A build-up of wax, dust, and germs was found. This procedure takes only one to two minutes. The cotton swabs were labeled with the participant’s number, 25 females and 25 males. After collecting the samples, all the swabs were immersed in peptone water and incubated at 37 °C for one hour before culturing. The swabs were then taken out of the peptone water to start culturing one by one using Sheep Blood Agar, MacConkey Agar, and Sabouraud dextrose Agar. All the samples were cultured in a single plate of each type of agar. The Streak Plate Isolation Method was applied using an inoculating loop flamed between streaks. All the plates were incubated at 37 °C for 48 h. After two days, we started reading the plates of different agars and performed essential tests such as Gram stain, oxidase, and catalase tests. The catalase test was done to distinguish between Staphylococcus (catalase positive) and Streptococcus (catalase negative). Table 3 shows the Gram stain of the organisms that have been found.

Data was entered into a computer connected to the MicroScan system (WalkAway 96 plus System) to identify the bacteria. Biochemical and susceptibility testing results are generated and interpreted by the MicroScan Lab Pro software v5.0 (https://www.beckmancoulter.com/products/microbiology/labpro-information-manager).

Each participant was asked to answer a self‑administered questionnaire, which was built using the Jotform website. The questionnaire consists of two parts with eleven questions. The first part was demographic characteristics (age, gender, and education level). The second part was to determine the habits of earphone use.

The participants were then sent to the hospital for an optional examination of their hearing level using the diagnostic audiometer (SA 204 TM Diagnostic AudioMeter, by Entomed). It is used to assess a patient’s hearing at different levels to determine the severity of hearing loss. A calm, soundproof room is used for the audiometry tests (supplementary Fig. S1). One ear at a time, the headphones are connected to a machine that delivers different tones and variations. For each tone, the doctor recorded the lowest possible volume that the participant could hear11.

Statistical analysis

Microsoft Excel 2024 and SPSS version 29 were used to input and analyze the data. To use the descriptive analysis, the number and proportion of categorical variables were resolved.

Ethical considerations

The study was performed in accordance with the national and international guidelines, and was ethically approved by the Regional Research Ethics Committee (registration number: 607–45-13,300 on March 29th, 2024).

Results

The demographic profile of the study population is described in Table 1. The total of males is equal to females, 25 participants each. The youngest participant’s age was 17 years, and the oldest was 50 years old (mean = 28.2 years). Regarding education level, 78% of the participants were bachelor’s degree holders. Table 2 describes the habits and symptoms of the participants through which we performed statistical analysis.

Table 1 Participants’ demographic characteristics.
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Table 2 Attitude of earphones’ use and related symptoms.
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Table 3 shows the results of the bacterial and fungal growth. Blood and MacConkey agars are used for bacteria, while the Sabouraud Dextrose agar is used for fungi. Female samples had growth in four plates in blood agar, as shown in Table 3. A7 and A22 have a few circular smooth convex colonies symbolized by (+ 1), while A10 and A16 have more circular smooth convex colonies symbolized by (+ 2) as in Fig. 1. Regarding male samples, B2, B7, B10, B12, B16, and B24 had bacterial growth. Similar to female samples, there was bacterial growth only in blood agar (Fig. 2). Both female and male samples have no growth in Sabouraud dextrose agar. The number of female colonies was 270 CFU\sample, while it was 230 CFU\sample for male colonies. Sixteen percent of female samples and 25% of male samples were positive. Interestingly, the bacterial isolates were different in females from those in males.

Table 3 Culture results of female and male samples.
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Fig. 1
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Sheep blood agar plate showing small circular colonies of female samples.

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Fig. 2
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Sheep blood agar plate showing small circular colonies of male samples.

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Gram stain and catalase test detected that all isolates were gram-positive and catalase-positive. The identified organisms are listed in Table 4. Antimicrobial susceptibility results for Staphylococcus species are shown in Table 5. Staphylococcus auricularis and S. capitis have almost the same results; both are susceptible to 22 antibiotics. Staphylococcus capitis was resistant to Fosfomycin. Staphylococcus hominis-novo was resistant to 6 antibiotics.

Table 4 Results of gram stain and catalase tests of identified organisms in the earphones of male–female samples.
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Table 5 Antimicrobial susceptibility results for Staphylococcus species.
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Based on our analysis, as in Table 6, (46.4%) of females and (53.6%) of males used earphones for 1–2 h per day with no significant p-value (0.335). In addition, (57.7%) of females and (42.3%) of males are having symptoms due to long-duration use of earphones, p-value (0.258). As shown in Table 7, a statistically significant correlation was found between having symptoms due to earphones and sharing it with others, p-value (0.037). Most of the participants (87.5%) have no symptoms and do not share the earphones, while 61.5% have no symptoms but share the earphones with others. There is no significant relation between age and having symptoms based on Pearson Correlation (− 0.161), p-value (0.263).

Table 6 Gender differences in daily use of earphones and having ear symptoms.
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Table 7 The relationship between having symptoms and sharing earphones with others.
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Hearing test was done to 30 participants using the SA 204 audiometer. Seven out of 30 (23%) are found to have abnormal results. Sensorineural hearing loss at high frequency was the main cause of abnormality in six out of the seven abnormal tests. The seventh had a conductive cause of hearing abnormality. Examples of the audiometric results are presented in the supplementary Fig. S2.

Discussion

Our study shows, in Table 1, that the young generations are the main users of earphones. Two-thirds of the users were under 30 years old. Table 2 shows that most users use earphones for less than 4 h daily but at a moderate to high level of volume. This, with the long-term use, has led to hearing issues such as pain in the ear, itchiness, headache, and decreased hearing, supporting what was stated by CDC1. Awareness of hygiene was higher (40%) than that previously reported by Alarfaj et al.3 (29.8%). Sachdeva et al.12 Reported that 49% of their participants don’t clean their earphones. In addition, 74% of our participants were aware not to share their earphones with others, while 75% in the study of Abdullah et al. were sharing them with others.

Based on the statistical analyses conducted, all relevant combinations of the study variables were examined for potential mediation and moderation effects. As shown in Table 7, a statistically significant finding was a direct effect between sharing earbuds with others and the occurrence of side effects (p = 0.037). In addition, moderation analyses were conducted to examine whether the relationship between daily usage and side effects might vary by other factors (gender, volume level, years of use). All interaction terms were found to be non-significant (p > 0.05), indicating that sharing earbuds with others was the only factor that significantly led to symptoms. El-Sakhawy et al. have also shown that sharing earphones was a risk factor for having positive bacterial isolates from the external ear canal13.

Regarding bacterial contamination, Tables 3 and 4 show that isolated organisms were all gram-positive. It was mainly S. auricularis for female samples, while male samples had grown S. Hominis and Capitis. El Magrahi et al.6 also reported that most organisms were gram-positive. Aleandri et al.14 have isolated different species of bacteria from earphone users, including Coagulase-negative staphylococci. In our study, the three isolated bacteria were Coagulase-negative staphylococci: S. auricularis, S. hominis, and S. capitis. Zainab et al.4 have reported different bacterial species: S. aureus and Pseudomonas aeruginosa. Regardless of the species found, the bacterial contamination found in our and these studies highlights the risks in sharing earphones.

Participants’ attitude toward earphones’ usage was compatible with that reported by Aljuaid et al.5. Both studies showed that earphones are commonly used in Saudi Arabia. Participants older than 41 (18% of the study’s population) use earphones much less than younger ones. Therefore, they did not report any symptoms. Most of our participants (84%) reported that they usually use moderate or high-volume level. Lee et al.1 reported that loud noise > 70 dB causes hearing damage and other symptoms. Table 6 shows that female users tend to use earphones longer than male users, although the difference was not significant.

Dermatological side effects were commonly reported by our participants. A third of the participants reported itchiness, and another third reported pain. One of the risk factors includes prolonged contact with the plastic or the rubber of the earphones in a moist environment, especially if they are continuously used for hours. Wax accumulation is another negative effect of the earphones, which may lead to conductive problems or even bacterial or fungal growth. Impactions of wax, otomycosis, otitis externa, itching, and otalgia were observed more frequently among earphone users in India and Saudi Arabia15,16. All isolated bacteria in our study, Staphylococcus auricularis, hominis, and capitis, have been reported to cause skin infections17. Chronic middle ear infections and wax accumulation were reported among headphone users18. This could explain that sharing earphones was a statistically significant factor in people reporting symptoms (Table 7). This also highlights the importance of the cleanliness and hygiene of the earphones. A study by Harshini et al.19 shows the related symptoms of using earphones include: ear pain (17%) and itchiness (13%); however, in our study, the percentage was higher for ear pain (34%) and itchiness (32%). Almost half of our participants (44%) suffer from headaches after using the earphones. Rekha et al.20 reported that 28.9% of headphone users suffer from poor concentration, and 13.6% complained of headache.

In our study, we found a statistically significant correlation between having symptoms and long-duration of earphones usage, as well as sharing them with others. This is consistent with Haewon Byeon’s study in which adolescents who used earphones more than 80 min per day in a noisy environment had a 4.7 times higher risk of hearing loss than those who used them less than 80 min per day21. Our results were also consistent with Kiran Naik’s study in which more hearing loss was found in those using earphones more than 2 h daily22. Regarding our hearing tests, 6 patients out of 7 have sensorineural hearing loss (SNHL) affecting high frequency, and 1 patient has conductive hearing loss. This is consistent with Kabir Haruna’s study in which 91.7% had sensorineural hearing loss, and the hearing loss at high frequencies were the most reported (64.6%)23. Sulaiman et al. have also found that extended high frequencies were affected, while conventional test frequencies were comparable to controls24. The increased hearing threshold might involve a broader range of frequencies in those using earphones for longer durations25. A Korean study has found an elevated hearing threshold in insert earphone users with a cumulative use period of over 5 years26. Earphones with a noise-cancellation feature are usually used at a lower volume level and might be considered safer15,27,28.

Limitations

The study covers an important subject from different aspects, including bacterial colonization, skin complications, hearing impairment, and non-specific symptoms. Nevertheless, there are some limitations in the design and size of the study. Being a single-center study with a relatively small population size is the main limitation. Future studies are advised to recruit a higher number of participants to be more representative, and to follow the patients with hearing loss after modification of their attitudes towards earphone use. In our study, the criteria to define a headphone user, and the prevalence of their use in the general population were not clearly detailed. Another limitation is that the audiometric assessment was done in another city, and many participants could not do it, although it was unpaid.

Conclusion

Earphones are commonly used among the young generation, hence the importance of considering possible complications of bad habits. Prolong periods of use and loud volume may affect hearing and cause sensorineural problems. Another complication of prolong period of use may include wax accumulation, conductive hearing impairment, and bacterial colonization. Sharing earphones with others might increase the prevalence of these symptoms and bacterial transmission. Public health campaigns and manufacturers should inform users about the risks of sharing earphones.

Future studies are recommended to involve a larger population size and to do bacterial and fungal cultures. It would be of interest to compare the various types of earphones to have an idea of safer designs to recommend, which would probably be non-insert ones.