Hearing Aid Fitting | August 2016 Hearing Review
The community-based Wide Frequency Audibility (WFA®) fitting method was created by the Starkey Hearing Foundation (SHF) to provide meaningful benefits for people with hearing loss across the globe. The method, which continues to evolve to meet the ever-growing need for hearing care, is simple, sustainable, and scalable. This article describes the WFA and the SHF’s community-based hearing healthcare model.
Efforts to help people with hearing loss in the developing world are ongoing and span the globe. These efforts are necessary because the numbers of people who experience hearing loss throughout the world, but for whom little or no assistance is available, is staggering. In sub-Saharan Africa, for example, it is estimated that more than 1.2 million children under the age of 14 have hearing loss of a moderate to severe degree bilaterally.1 The World Health Organization (WHO) global estimate for disabling hearing impairment (of a degree of severity >40 dB HL for adults and >30 dB HL for children in their best ear) was at least 278 million in the better ear in 2005, and the 1995 disease burden estimate tripled to about 360 million in 2015. It is on track to hit half a billion people in 2025.2 Two-thirds of individuals with hearing impairment are estimated to live in developing countries.2
For the continent of Africa, the ratio of audiologists to people with hearing loss is one for every million people. Not all hearing healthcare providers are audiologists, but even when others are included, the WHO estimates that fewer than 1-in-40 people who are in need of hearing aids for their hearing loss receive them.4,5 Indeed, the WHO has stated:
“Hearing aids and cochlear implants are prohibitively costly in low-resource countries. And as current designs do not allow for long-term use, replacement costs also make these devices out of reach of poorer countries. In addition, batteries for hearing aids are relatively expensive and have a short usable life in hot and humid climates. Follow-up services for hearing aids by trained technicians are also generally costly…WHO estimates that global production of hearing aids meets less than 10% of the global need for these devices. Development of appropriately designed and affordable hearing aids and cochlear implants for use in different age groups and contexts is urgently needed.”4
Many governments in developing countries lack resources to work on the problem of hearing healthcare for their people.6 A lack of government support results in health systems in many developing countries being too weak and fragmented to enable the scaling-up of essential preventions and interventions required for adequate hearing healthcare.
The inability of governments in countries with limited budgets to cater to diverse health needs has led to a growing trend towards local public-private partnerships for healthcare delivery in low- and middle-income countries.3,4 Also, in an effort to improve the lives of people with hearing loss in countries where hearing healthcare is unavailable, the WHO developed and published a “primary ear and hearing care training resource”7 to provide basic knowledge and skills in hearing heathcare to support training efforts in countries where such training is currently not available.
The Starkey Hearing Foundation (SHF) has been working on providing hearing healthcare in the developing world for many years. Initial efforts were focused on providing hearing aids and fitting individuals with hearing loss. However, as the foundation’s creators recognized the need to do more to bring about lasting changes, they have expanded the program to meet the need. The SHF has developed a working community-based model for assisting people with hearing loss. The SHF model helps accomplish the goals of the WHO Primary Ear and Hearing Care Training initiative7 and is designed to provide assistance in a manner that is simple, sustainable, and scalable.
The SHF has made a conscious decision to simplify the process of distributing their hearing aids to people so that as many people as possible can benefit. Additionally, this simple method is easy to learn so that local citizens of developing countries can be taught the method and be able to help their own citizens.
William F. Austin, founder of Starkey Hearing Foundation, has developed the Wide Frequency Audibility (WFA®) fitting method. The WFA® method is one piece of the larger community-based model the SHF has put in place to both provide hearing aids and to develop hearing healthcare for people who are not receiving such care across the world. This paper is designed to describe both the WFA® fitting method and also the community-based model in which it functions. The SHF community-based model of hearing healthcare is divided into four phases:
Phase 1. Patient Identification
The first phase of the program involves the identification and training of local partners and community-based health workers, as well as identification, screening, and provision of primary ear-care services to potential hearing aid candidates.
To ascertain hearing loss, screening is performed using a modified whispered voice test.8 Those who fail the test (monaurally or binaurally) have their ear impressions taken by the trained team under supervision that will be used in the provision of custom earmolds for the patients. Patients’ demographic, baseline socioeconomic status, and hearing health data is documented at this Phase of the program.
Phase 2. The WFA Fitting Method
Current fitting methods in the developed world are heavily dependent upon technology to both program and verify the function of hearing aids. As mentioned previously, methods less dependent upon technology and that can be implemented by individuals with minimal training are needed in the developing world.4,7 The WFA® method is a simplified comparative fitting approach9 that is similar to comparative approaches that were employed in the developed world before the technology-dependent methods of today came into being.10 The method is easily adaptable for use within different cultures and across languages.
Three objectives of the WFA® method guide the fitting process: 1) Audibility and physical comfort; 2) Prevention of loudness discomfort, and 3) Binaural balance. These objectives are targeted in Phase 2 of the SHF community-based model, where each previously identified patient is fit with hearing aids and custom ear molds. The three objectives can be thought of as steps in the process.
Step 1. Ensuring audibility and physical comfort. Step one of the fitting process is to begin with one ear and ensure that the physical fit of the earmold and hearing aid together are such that the person can wear the hearing aid comfortably. The examiner then uses speech sounds at an average intensity level, and the person being fit is asked to indicate either through an interpreter or through gestures whether he/she feels the speech to be “too soft,” “just right,” or “too loud.” Adjustments to the volume control are made and feedback from the patient is elicited for each adjustment.
Multiple power levels of hearing aids are available to the person fitting the hearing aids for use in the comparative approach. The person fitting the hearing aids always begins with the least powerful instruments and moves to higher power aids sequentially, so as to not over-amplify the person with hearing loss. The comparison process is continued until he/she reports the fit to be comfortably loud.
Step 2. Preventing loudness discomfort. Once behaviorally acceptable audibility is established for each ear independently, Step 2 commences when both hearing aids are placed on the patient and the examiner asks the person being fit to indicate whether the fit is comfortable. Further adjustments are made as necessary to establish that the patient has both audibility and comfort from the fit of the two hearing aids. The settings of the volume control are given close attention at this point to ensure that the person being fit finds the hearing aids to be comfortable at a volume control setting that provides reserve gain and also the ability to reduce gain when desired.
Step 3. Attaining binaural balance and instruction/counseling. Finally, with the hearing aids fit comfortably on the patient, the person fitting the hearing aids checks to see if the patient feels the sound from the hearing aids is balanced. The check for binaural balance is accomplished by alternating sounds between ears at the same approximate distance and intensity. The binaural balance of the hearing aids provides for both listening comfort and also increases the likelihood that the person can localize sounds in his/her environment.
When the fitting process is completed, the hearing aid(s) recipients receive counseling on how to care for their hearing aids. They are also provided with aftercare information on where to go and how to contact the hearing care coordinator for follow-up services. Parents, teachers, and others who accompany the person to the hearing aid fitting are also given this same information.
Selection and training of local program teams to execute ongoing program activities also takes place during Phase 2. Patient data is also updated during this visit and the care provided is documented.
Phase 3. Aftercare Program
Phase 3 is a follow-up phase. Local partners through community-based hearing care coordinators conduct outreach to provide aftercare services to patients within the first 60 days after receiving hearing aids. This is done through the phone, school visits, or at designated centers within the community. The community-based team provides ongoing monthly aftercare services at a central location, giving patients access to additional care including basic ear care, more counseling and instruction, batteries provision, and free services to repair or replace hearing aids when needed. Furthermore, patients, team, and program progress is assessed through the SHF monitoring and evaluation framework, and the SHF training team keeps providing ongoing education for the program team. The local team also utilizes this phase to identify new hearing aid candidates for future Phase 1 initiatives.
Phase 4. Listen and Speak
SHF’s Phase 4 is a new offshoot of the Phase 3 program, and it is about providing children with the opportunity to learn how to listen and speak. As the SHF team traveled around the world, they have fit many students who have mild to severe hearing losses but have limited or no speech in “schools for the deaf” with hearing aids. Throughout the world, children with hearing loss are being labeled and put into “schools for the deaf” regardless of the severity of hearing loss. This has effectively deprived many children the opportunity to learn to listen and speak, cutting them off from real opportunities to communicate with the majority of people in their country who are part of the normal-hearing world.
In Phase 4, we identify children with lesser degrees of hearing loss and help develop their communication skills with the goal to get them to a level where they can be mainstreamed into a normal-hearing classroom. For children with profound hearing loss who cannot learn spoken language fluently, they are being taught basic spoken communication skills, and they continue with sign language instruction to develop their language and cognitive abilities.
The SHF trains teachers in schools for the deaf to incorporate audition, speech, and language into their everyday curriculum along with sign language. The teachers then require their students to vocalize and sign their answers back. Local SHF staff work alongside local speech-language pathologists (where available) to support the children and teachers in the schools. School visits are made to encourage the teachers in the classroom and to advise them as needed.
The SHF Phase 4 staff also holds parent trainings to educate them about hearing loss, hearing aids, and to teach them the necessary skills to work on speech and listening at home. SHF staff members make weekly phone calls to the parents to ensure that the children’s hearing aids are working and to discuss how the speech techniques are being used.
As is important to all phases of the SHF model, local teams are being created to carry out this work. By creating local teams, SHF can efficiently and effectively provide a model that is continuous and sustainable for long-term change and mass impact.
Benefits of the Model
The SHF Community-based model with its four phases, including the WFA fitting method, is designed to provide hearing healthcare to individuals around the world who are not receiving such care. The model is designed to fill the need identified by international organizations like the WHO that have recognized an urgent need for simplified methods to provide as much care for as many people as possible; the alternative is that these individuals will not receive any care at all throughout their lives.4
In response to the dire need for hearing healthcare, the WHO produced a 3-level training system that includes basic training for primary caregivers, intermediate training for local providers with minimal training, and an advanced training module for professionals with higher-level training.7 The WFA fitting method and the SHF Community-based model are ideally suited to bring resources and knowledge to developing countries to train local providers at the intermediate level.
The SHF has made a conscious choice to simplify their model to try and provide opportunities for as many people across the world to hear and have the opportunity to develop communication skills through auditory-verbal means. The Community-based model is designed as a sustainable and scalable effort. The model is sustainable because local individuals are being taught the simple skills to apply it and maintain it after the SHF has left the country. The model is simple enough that it can be scaled up or down, as necessary, to meet the needs of the tens of thousands of people in each developing country that are not receiving any hearing healthcare presently.
It should also be noted that implementation of the SHF model does not hinder developing countries from educating and hiring more educated professionals to match the advanced training level of the WHO, or even to adopt the university training model of many developed nations. Indeed, it can be argued that the work of the SHF in fitting hearing aids and training intermediate-level hearing healthcare workers will ultimately create a market within developing countries for professionals with more advanced training in hearing healthcare within which they can work.
The SHF is keenly interested in providing real benefit for each and every individual fit with hearing aids through the model. Even though the methods are simple compared to modern techniques, people fit with the model are receiving measurable and sustained benefits. Subjective reports from people fit with the WFA method has indicated that a large majority (>85%) are very satisfied with the benefit they are receiving. More objective data is in the process of being collected and will be published in the near future.
The SHF community-based model with its WFA hearing aid fitting method is providing meaningful benefits for people with hearing loss across the globe and will continue to evolve to meet the ever-growing need for these services. The model is simple, sustainable, and scalable. For the many individuals across the world who need help with their hearing to be able to communicate effectively, programs like this will continue to provide valuable care. ?
WFA® is a registered trademark of the Starkey Hearing Foundation.
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Correspondence can be addressed to Dr Larsen at: [email protected]
Original citation for this article: Larsen JB, Lawal L, Mukara BK, Mulwafu W, Ndegwa S, Mwamba A, Fabry D. A Community-based Hearing Healthcare Model and the WFA Fitting Method. Hearing Review. 2016;23(8):36.