Trial of Affordable Bone Conduction Headphones to Support a Deaf Child's Education in Malawi

Abstract

A 13-year-old child with hearing loss secondary to chronic serous otitis media and bilateral tympanic perforations had been unable to hear the teacher at school and unable to pass end-of-year exams. In 2020, she trialed a bone conduction headset paired by Bluetooth to a remote microphone and used this to support her hearing at school, socializing with friends and in the family home. Due to the COVID (COronaVIrus Disease) pandemic and a cholera epidemic, she was followed up 3 years later. The child (now 16 years old) reported using the headset every day for 3 years. Able to hear the teacher, she reported having passed school exams every year since using the device, and now had ambitions to study medicine.

Key Points

1. Access to communication and education is possible with affordable, bone conduction headsets paired with a Bluetooth microphone.

2. Affordable hearing technology was able to be used after one initial explanation (without written instructions nor video support) and supported a child's hearing for 3 years without the need for interim healthcare appointments.

3. Children could be provided with hearing support remotely, enabling them to access hearing face-to-face (such as at home or school) or on-line.

Introduction

An affordable headset and microphone supported one patient's hearing in Malawi; this was reported to continue for 3 years enabling her to access communication and education more easily.

In 2022, World Health Organisation (WHO) and Unicef released a report ¹ to call on governments, industry and donors to fund and prioritise access to assistive products that can affordably support health education and medical conditions. ¹

It is estimated that 2.5 billion people need one or more assistive products, with hearing technology and access to health apps listed as priority areas. The WHO director general speaks about lack of access to assistive tech as being an “infringement of human rights.” The mission of the WHO World Hearing Forum is to “Make ear and hearing care accessible for all.”

Middle ear disease is found in nearly half of Malawian children with hearing loss. ² Eleven percent of 4- to 6-year-olds have bilateral hearing loss. ²

Hearing loss affects speech, language, education, mental health and employment prospects. ³

Past efforts to provide hearing support with donated hearing aids in Malawi have been challenging even with generously donated equipment since conventional, behind-the-ear (BTE) hearing aids require regular battery changes that have been difficult to continually source and fund locally. The high incidence of chronically infected ears or chronic serous otitis media—where the patient has continuous ear discharge—means that conventional BTE hearing aids cannot be worn, even if available. Bone conduction (BC) hearing aids, which are more suitable in cases of ear discharge, are between 2 and 20 times more expensive than BTE hearing aids and also require batteries to be sourced. BC hearing aids are therefore even harder to access.

Headphones that use BC technology are more affordable than hearing aids ⁴ and do not require batteries: They are charged in a similar way to mobile phones using either a charging cable connected to an electrical socket or to a solar-powered charging pack (which are widely used in many houses, schools and market stalls in Malawi) . BC headphones can be used to care for patients remotely.^5,6 They do not need a trained healthcare professional to monitor or program the devices in a hospital. ⁶ BC headphones can enable children with conductive hearing loss to hear quieter speech when they are paired to a microphone worn by a speaker such as a parent or teacher. ⁵ This enables children to hear the speaker over background or environmental noise, which is the most challenging listening situation for those with hearing loss. ⁷ BC headphones/headsets can also be paired to a computer, tablet, device or phone for on-line learning, tele-health opportunities and mobile communication. ⁶

The device can be valuable for middle ear-related hearing loss, because it uses BC technology which sends sound as a vibration across the cartilage and bones of the skull to reach the inner ear (cochlear) thereby bypassing the ear drum and middle ear (which in this patient was damaged by chronic serous otitis media and persistent perforations in the ear drum and causing hearing loss).

The most common cause of childhood middle ear hearing loss is a condition called “glue ear” (also known medically as Otitis Media with Effusion, OME) where fluid builds up behind the ear drum, which can happen after an upper respiratory tract infection or ear infection. Eighty percent of all children will experience this at least once in their childhood, ³ but some children experience this much more frequently. Data from European children who have school-entry hearing screening assessments shows approximately 1 in 10 children starting school have hearing loss from OME. ³ Children exposed to overcrowded living conditions, poor nutrition, and smoke from cooking or cigarettes are more prone to glue ear. In remote areas of Australia within aboriginal and Torres Strait Islander communities, (which may have some parallels with rural Malawian populations), around seven out of 10 children start school with glue ear or OME.

Parents who trialed the headset and microphone in the UK in a research study using the devices for remote care during the COVID pandemic ⁶ had many comments such as follows:

“I wish I had filmed it when he first tried it on, he said “I can actually hear’”

“He says to everyone, “I can actually hear you now.”

“She speaks more normally [when wearing the headset], phonics at school - she is pronouncing ‘ch’ and ‘m’ clearer.”

“He used to get the next door neighbour's name wrong but when he said it right the other day, we was all shocked, even she was shocked.”

“He speaks at a better volume level himself when he is wearing headphones.”

“His speech is coming on so well in just a week.”

“There is a quite a change in how he is saying words. He is able to correct himself more easily when wearing the headphones.”

The BC headset is visible when worn, much more noticeable than a conventional BTE hearing aid, and because of this, acceptability and views around any stigma around the device were investigated. In the UK, families had found the device more acceptable than a hearing aid because it didn’t look like a hearing aid and looked more like a “cool” set of headphones. Some children in the UK had commented: “my friend wants one” or “my friends said ‘when you were wearing the headset you look like a rock girl’.”

Some parents commented:

“He thinks it's pretty cool, he thinks it's like a robot-like thing.”

“He is very protective over his headphones. The teacher was worrying about them getting damaged and I said ‘no fear, he won’t let anyone touch them’.”

“The headphones give a visual cue to others that she has a hearing loss.”

Case Report

A 13-year-old child with a history of multiple ear infections, chronic serous otitis media and bilateral tympanic perforations, presented to the Audiology department in Blantyre Malawi in January 2020. Figure 1 shows the patient's audiogram at presentation, with a significant conductive hearing loss. Tympanoplasty was recommended but was unable to be arranged due to cost, waiting list problems, the covid pandemic followed by a cholera epidemic.

Figure 1.

(a) Audiograms show that in 2020 when the child was 13 years old and had perforations in both ear drums and chronic ear discharge (chronic serous otitis media), the child presented with a severe to profound hearing loss. The left ear (represented by crosses on the graph) hearing sounds between 70 and 90 dB and the right ear (represented on the graph as circles) between 80 and 100 dB AC (Air conduction). Masked bone conduction (shown as square brackets on the graph) shows what appears to be an underlying sensorineural hearing loss which raises the question about whether the cochlear was affected by inflammation or infection at the time or whether the masking had to be so loud to compensate for a severe conductive hearing loss that it invalidated the bone conduction thresholds. The positive response to the bone conduction devices meant that the latter explanation was perhaps more likely. (b) The second audiogram, 3 years later in 2023, shows the child can hear across the frequencies (0.25, 0.5, 1, 2, 4, 8 kHz) between 30 and 50 dB which is defined as a mild to moderate hearing loss and masked bone conduction thresholds were within normal range. At this point, both ears were free of discharge with improvements in the size of the patient's tympanic perforations.

As a result of patient and public involvement work for the ethically approved “Listen Hear” study, the audiology department had access to affordable BC devices paired via a Bluetooth microphone (Figure 2).

Figure 2.

The affordable bone conduction device (consisting of headset and microphone) costing £100 that was given to the patient in January 2020. (a) January 2020: The device given to the patient. (b) January 2023: After daily use for 3 years in the classroom, to socialize outside and using the device at home to hear her mother, the device had taken some knocks but was still working. A friend has trodden on her bag at school and the headset had become damaged, but they had repaired it with sellotape and managed to keep it working. The child has not seen a health care professional for 3 years but had managed to hear and access education in that time.

The child was shown, along with her parent, how to use the headset by the audiologist at the initial appointment in January 2020 and due to significant delay caused by the COVID pandemic, was followed up 3 years later in January 2023. No written instructions were provided. Consent and assent have been obtained from the audiologist and patient, to record, use and reproduce the data, quotations and images shown in this case study.

Method

This case study was part of patient engagement work to assess the acceptability, functionality and usability of the headset in a health care service in Malawi. Initial engagement with staff indicated that there would be interest for this device, based on the ease of use, no requirement for batteries, and that patients could still wear the device with ear discharge which is prevalent in Malawi: Chronic serious otitis media affects 5.4% of Malawian population with “a high burden of middle ear disease and preventable hearing impairment in school-entry age children in rural Malawi”. ⁸ Patient opinion was sought, by recruiting two young Malawian people from the audiology clinic who had a confirmed conductive hearing loss where no further interventions were available. Recruitment criteria also included age between 11 and 14 years, who consented/assented and were willing to try out the product and give honest feedback. The patients were offered to try the headset at home between appointments and report at the follow-up appointment 3–6 months later, whether they had been able to switch it on, pair it to the microphone or computers/ phones/ devices and whether they were able to charge it at home. It was important to know whether patients found the headset acceptable and what their friends and family thought of it. It was also important to understand which circumstances patients had considered using the headset (home/ socially/ school/ telephone calls/ television/ etc), whether it was comfortable enough and which listening situations the headset was considered to benefit people the most.

The COVID pandemic interfered with the follow-up. When follow-up was arranged one child was no longer contactable, however, the child's teacher had written to the audiology department informing them that the child was using the headset in school. The second child was contactable and is the source of this case study.

Results

Without healthcare professional involvement over the 3 years between appointments, the child reported using the headset every day, at school, when socializing with friends and at home. Hearing support at school was reported to be the most valuable listening situation, since the use of the headset (worn by the child) paired to the remote microphone (worn by the teacher) had provided clear access to the teachers voice over background noise which had improved the listening environment by reducing the sound to noise ratio for that child in a classroom of 86 students. The child explained that when wearing the headset in the classroom “you are only concentrating to the teacher, not your friends. Even your friends, they can talk much, but you can’t hear them, but you can only hear the teacher when he or she needs to teach, so it makes someone to be active in the class.”

Although the patient in Malawi still had holes in their ear drums (tympanic perforations) and therefore would not have been a suitable candidate for a BTE hearing aid which delivers amplified sound to the ear drum, the child was shown a smaller, less-visible, BTE hearing aid as a comparison with the headset to see which device would be more desirable. The patient said that she didn’t mind wearing the headset, that her friends were keen to play with her because they were interested in her device, that her friends called the headset her “Beats®” (like the commercially available Beats electronics headphones) and she commented “so others they think that this is my Beats, we call it my Beats. They used to put it in my case and they can hear the sound and they say ‘can I have your beats so that I can hear my music?’ and I tell them ‘No!’.” They say that they are interested in them and so I have got so many friends because they wonder what is this and so they want to share it and play with it and play with me’. The patient also noticed that one problem would be that a BTE hearing aid would amplify all sound, whereas to succeed at school she needed to hear the teachers voice over background noise.

Discussion

Findings

This case demonstrates that an affordable Raspberry Pi headset (costing 25 British pounds or 25 000 Malawian kwacha) and Bluetooth microphone has been sufficient to support a child's hearing for 3 years in Malawi and for the child to report ease of use, acceptability regarding wearability and comfort, as well as reporting improved access to education. Health professional involvement had not been available during that time but the patient had been able to self-manage her hearing loss for 3 years.

The child found the headset acceptable to wear at school, at home and with friends. Similar acceptability has been recorded in UK studies where children have reported that it “looks cool” and when given the choice 56% of UK children, with OME-related hearing loss, chose to take the headset to use in school ⁶ (although no data could be found to try to compare this to acceptability of BTE hearing aids. The stigma surrounding BTE hearing aids is still prevalent in many communities, and in Malawi, audiologists spoke about difficult times in the past where people with cochlear implants had been labeled as “blood suckers” and subsequently treated badly by members of their community).

This case demonstrates that children with the most common type of hearing loss can be supported to access education and during times when it is difficult to access health care (such as during the covid pandemic, cholera epidemic or due to difficulties accessing health care). A child's hearing could potentially be supported remotely for long periods of time. A study in the UK which used the same equipment during the covid pandemic ⁶ demonstrated it is possible using the kit to support children remotely using follow-up by telephone or video-call.

Programmable hearing aids require follow-up appointments with audiologists in Malawi; usually around four times during the first year and annually thereafter. Similar follow-up protocols are used in UK. The BC device used in this case did not require programming or specialist follow-up.

The device was able to be understood and set up by the 13-year-old patient and her mother after one verbal explanation. This case shows that an initial explanation could be sufficient, if not ideal. No other instruction, written information nor on-line information was provided in this case, but, reportedly, the family were able to use the device for 3 years after the initial consultation without any further support or contact from an audiology professional.

The device does not have batteries: It is charged, much in the same way that a mobile phone is charged. The patient had managed to charge the device from a wall socket and plug whenever she wasn’t using it or over-night to ensure she could use it consistently during the day when she needed it most. However, solar power chargers are readily available and used routinely in households, schools, organizations and market places in Malawi, providing a cheaper and sometimes more consistent and reliable electricity supply than the national power supply. The cost of the device plus a solar-powered charger given to patients can still be more affordable than the cost of a BTE hearing aid.

Limitations

Although the child reported subjectively difficulties passing end of year exams prior to using the headset and success at passing end of school exams (the national Junior Certificate exams), however, other factors could have been contributing to greater academic success over 3 years such as child development, improved listening and concentration skills, effective teaching and changes to the severity of the child's hearing loss.

Although the child reported consistent hearing difficulties between appointments, there are only two audiograms recorded by an audiologist at the beginning and end of the 3-year period and therefore hearing levels are not consistently known. On both occasions, the same audiologist observed and documented a hole in both eardrums (bilateral tympanic perforations), and it was recorded that the tympanic perforations would need surgical repair due to the low likelihood of spontaneous resolution. However, like many patients, surgery is unlikely due to only one Ear Nose and Throat surgeon operating in Malawi. Due to tympanic perforations being recorded on both occasions the child was seen, it is unlikely that the patient had any episodes of resolution and therefore unlikely that hearing was within the normal range during the 3-year period. Multiple literature sources support the association between the levels of hearing loss seen in this case and difficulties accessing communication and education. ⁸

The child reported not having passed previous end of year exams at school prior to using the headset. Since being given the headset, the child reported using the headset daily, but this was not recorded in a journal, diary or checked by a researcher. However wear and tear to the product was evident 3 years later (see Figure 2): All markings on the microphone had been rubbed off, the black plastic coating of the microphone had been worn down to the bare metal in places. The child had tried to reinforce the sides of the headphones (Figure 2). This was consistent with regular use of the product.

Conclusion

This case demonstrates that a simple, affordable, low-cost kit comprising of a BC headset and microphone has been used to support a child's hearing remotely in Malawi for 3 years, over the COVID pandemic, when health services and health professionals could not be accessed. Further research is needed to establish whether this device may be able to support more children with hearing loss in Malawi and whether this could improve access to education.