Adverse Effect of Inadvertent Use of Earphones on Hearing and Its Prevention

INTRODUCTION

Technology is the most necessary evil of our times, and one such necessity currently is that of earphones/headphones.¹ In daily life, we use earphones very often while taking an early morning walk, boarding a metro, traveling on a bus, sipping coffee in a café, just a call to the office, or attending Google Meet. Throughout the day, we encounter several people listening to music or talking through earphones. However, by letting your earphones be plugged in too much, we might not be disturbing the people around us, but our hearing is certainly harmed unknowingly.

Hearing loss is an extremely common medical condition, progressing in incidence and severity with age.² It affects all age groups, from neonates to elderly patients, and is nearly omnipresent in the 60+ age group.^3,4,5 As per World health organization (WHO) estimates, in India, there are approximately 63 million people who are suffering from significant auditory impairment; this places the estimated prevalence at 6.3% in the Indian population. As per the National sample survey organization (NSSO) survey, currently, there are 291 persons per 100,000 population who are suffering from severe to profound hearing loss (NSSO, 2001). With such a large number of hearing-impaired young Indians, it amounts to a severe loss of productivity, both physical and economic. An even larger percentage of our population is unaware that they are suffering from milder degrees of hearing loss.

Our ear processes not only useful signals like speech but also unwanted signals like noise. Speech is a demand of the community to establish a better relationship with the community; it is necessary for the enhancement of knowledge, skills, and evolution of mankind. Communication can be made in a direct, face-to-face manner or indirectly by using tele-technologies.

The exchange of information through telecommunication to acquire knowledge and to serve a large number of the population is a need of society. Human beings are nothing alone; they indeed need each other for their social development via communication. Any disease or pandemic can stop humans from traveling to share their experience and knowledge but cannot stop their telecommunication. The excessive and inappropriate use of earphones for longer durations has led to anxiety and high-frequency subclinical hearing loss, which has the potential to cause early onset of age-related hearing loss in the near future.

MATERIAL AND METHODS

A total number of 2756 subjects with an age range of 18–40 years were included in this study who came to our department for the hearing evaluation. Out of those 2756 individuals, 216 individuals were segregated and had a history of usage of headphones or earphones during work from home, online teaching, telepractices, and various entertainment purposes. Individuals who had any associated problems and a history of previous hearing loss were excluded from the study. Subjects who were having a history of telepractice, attending online classes, Google Meet, and other online activities using headphones during the COVID-19 pandemic were included in this study.

In all the individuals, pure tone audiometry (PTA) and impedance audiometry were carried out. Impedance audiometry was carried out to rule out any middle ear pathology. PTA was carried out to find the Speech Average Loss (SAL) Index, Early Loss Index (ELI), and percentage of hearing loss. PTA was administered using an Inter-Acoustic AC 40 dual-channel diagnostic audiometer, and impedance was administered on a grason-stadler instruments (GSI) Tympstar instrument.

SAL—The SAL index evaluates the conversational frequencies at 500, 1000, and 2000 Hz and then takes the arithmetic mean of the hearing loss in decibels of these frequencies and establishes a classification in grade from A to G according to the worsening of the worker’s hearing; thus, a SAL-A grade indicates that both ears are within normal limits, while the SAL-G grade indicates total deafness.⁶

ELI—This index is calculated by subtracting a correction value for presbycusis from the loss at the 4000 Hz frequency (weighting the loss according to the age and gender of the subject). It is evaluated according to an increasing scale A-B-C-D-E, from greater to lesser hearing capacity, assessing the two ears individually.⁷

The percentage of hearing loss was calculated using the formula and results given in the rights of persons with disabilities (RPWD) Act 2016, Gazette of India, which includes the pure tone average thresholds of 500, 1000, 2000, and 4000 Hz. The values of thresholds in these frequencies divided by 4 will give the pure tone average of one ear, and the other ear average will be calculated in the same manner. Then, the binaural percentage of hearing loss will be calculated with the use of the formula “better ear percentage multiplied by five subtractions of poorer ear percentage then divided by six.”

The methods, including PTA, SAL, ELI, and percentage of hearing loss, will provide information about the early onset of hearing loss.

RESULTS

The result of our study shows that all the individuals who came for a hearing evaluation and have a history of long-duration usage of earphones or headphones have their hearing compromised at higher frequencies. With continuous and long-term exposure to loud music, the hair cells eventually lose their sensitivity to vibration. Sometimes, the loud music also results in the cells bending or folding over, which leads to the sensation of temporary hearing loss. The hair cells may or may not recover from these extreme vibrations. However, even when they recover, they mostly cannot function normally, which can cause permanent hearing loss or deafness and is almost impossible to recover from. Out of 216 individuals, 56 individuals were having hearing loss in the 3–6 kHz region in PTA tests. In the rest of the individuals, other frequencies were also affected.

The SAL Index reveals that 145 individuals had normal ratings on the scales, and all others had ratings on the SAL Index. The major drawback of this rating scale is that it only considers the hearing sensitivity of the better ear and ignores the evolution of the poor ear [Table 1]. This index only considers the hearing thresholds at 500, 1000, and 2000 Hz, whereas the individuals who use earphones and headphones for longer durations have more losses at the frequency range between 3 and 6 kHz. Hence, this index fails to early identify the harmful effects of noise or music exposure. This is why the SAL index is more useful in cases where the individuals have hearing loss at all frequencies and specifically at low and mid frequencies.⁸

The results of the current study can be analyzed by the following tables.

ELI: Like the SAL index, this ELI considers only hearing sensitivity at 4000 Hz, which is a characteristic of noise Induced Hearing Loss.⁹ Hearing loss of its adjacent frequencies is dependent on the duration of the noise exposure.^4,10,11,12 The result of the present study shows that in ELI, Most of the individuals in both ears show the grade of hearing Type A (Normal Excellent), B (Normal Good), and C (Normal) [Table 2]. The major disadvantage of this method is that it only considers the hearing loss at 4 kHz, and thus, it does not detect all the pathologies.¹³ One example of this would be high-frequency hearing losses, undetectable on this scale, which have been reported by several researchers in the 12 kHz frequency range.⁵

Percentage of Hearing Loss: The percentage of hearing loss was calculated using the RPWD Act 2016. Not all the individuals in the present study had the percentage of hearing loss less than 40%, which does not fall in the disability.

As we all know, hearing sensitivity decreases with the progression of age. In some people, the rate of reduction is slower, while in others, it is faster. Minimal hearing loss can be caused by noise exposure or using headphones at a higher intensity. This problem may create a severe impact on later life. We are surrounded by noises like traffic, construction, music, etc. If these sounds are at a safe level, that is, 80 dB for 8 hours, then they will not be harmful to our sensory mechanism, but as the intensity increases by 5 dB, then the duration of exposure must be reduced by half, that is, 4 hours, as per Occupational Safety and Health Administration (OSHA).

DISCUSSION

The primary concern with the headphones is the volume exposure that they give the ears, especially when used for uninterrupted, prolonged duration. Earphones are capable of producing very loud levels of sound very close to the ear and, hence, they are very dangerous. Most of us, over a time period, unintentionally become accustomed to using headphones/earphones at higher volumes, which may induce ongoing permanent hearing loss.^14,15,16 Both the intensity as well as duration of noise exposure determine the potential for damage to the hair cells of the inner ear.^17,18 The AirPods and their molds are kept anywhere without even regular cleaning, which unintentionally exposes them to germs, leading to a source of infection. Also, sharing the earphones paves the way for the transfer of these germs.

Some of the harmful ways in which earphones can affect our ears are:

Noise-Induced Hearing Loss (NIHL): A ringing sensation in the ear caused by damaged hair cells in the cochlea can lead to buzzing or roaring noise in the ear called tinnitus. More than 50% of the people who suffer from tinnitus are prone to developing high sensitivity to normal environmental sounds, which is referred to as hyperacusis. Loud music or long exposure tends to make the hair cells bend down too much; the extent of which can lead to temporary or permanent hearing loss, as once they are damaged, they are incapable of regenerating due to the limited number of hair cells.^19,20 Moreover, the increased pressure in the ear canal due to loud noise can also cause dizziness.

Ear infection has also been seen to rise as the earphones are directly placed into the ear canal, blocking the passage of air, which enhances the chances of infections in the external auditory canal. The regular and long-term use of earphones also increases the growth of bacteria. These bacteria stay on the earphones and, with more usage, infect the ear, leading to an increasing incidence of tragal perichondritis. Using the earphones for a long time also stimulates ceruminous glands, which causes excessive earwax, accelerating the chances of hearing difficulty, earache, and frequent ear infections. Long-term usage of earphones, as well as using earphones that are poorly fit, can induce pain that can often extend to the inner ear as well, leading to soreness in the vicinity of the ear. The electromagnetic waves that the headphones generate result in problems for the brain as well in the long term. High decibel noise levels withdraw insulation from nerve fibers that carry signals from the ear to the brain.

CONCLUSION

This study revealed that the inadvertent use of electronic gadgets such as earphones or headphones for the purpose of business, learning, entertainment, and telepractices may harm the ear and may cause permanent hearing loss if not used appropriately. One can save the ear through rational use of earphones by being aware of the consequences and with few habitual changes. So, awareness regarding the appropriate use of headphones and earphones should be created by healthcare professionals and audiometrists among the population to protect against the early onset of noise-induced hearing loss and Presbycusis. Healthcare personnel and audiologists should make society aware of the rational use of earphones and headphones to avoid early-onset hearing loss as well as high-frequency hearing loss. Further counseling of affected individuals diagnosed with mild hearing loss or NIHL should be done to change their habits, avoid loud noise exposure and ototoxic drugs, and take neuroprotective agents or antioxidants to prevent further hearing loss. Moreover, the majority of the population is not using plugs of the appropriate size, leading to more patients coming with otalgia due to ear canal involvement. So they should be made aware to use the appropriate size of earplugs/headphones. Also, one should avoid sharing earphones with colleagues, as the bacteria from one person’s ear can transfer to the other person as well; therefore, regular sanitization of the AirPods to stop a buildup of bacteria, sweat, and shredded dead skin around the earbuds should be done. Healthy auditory practices should be followed.