Development and evaluation of a theory-based intervention to increase infant hearing aid use:steps towards improving deaf children's language outcomes

There are around one in 1000 babies born with permanent hearing loss, which means it is one of the most common chronic conditions in children. Around 95% of these children are born to hearing parents who have little to no experience of deafness, and these parents usually choose for their child to use spoken language (even those that choose to use sign language). Being able to hear speech sounds is critical to this goal. Any level of hearing loss can make a baby's language learning journey harder because access to sound is effected to some degree, meaning they are at significant risk of delays in language development. These delays can have long-term effects on school readiness, later academic achievement, social and emotional development, employment, and mental health.

For deaf children (label used here to describe children with any degree of hearing loss), hearing aids are a key part of the support they receive. This is because they help babies access speech sounds, which are critical for spoken language development and to develop the auditory parts of the brain, especially in the first year of life. By getting hearing aids from an early age and using them consistently, babies are more likely to have better language outcomes.

However, research has shown that: 1) hearing aid use in the early years is inconsistent; 2) babies are not wearing their hearing aids as often as they need to for optimal benefits; and 3) caregivers face a number of things that can get in the way of achieving consistent hearing aid use. Any reduction in hearing aid use - even if it's only partial - limits experience with sound and access to spoken language, which can lead to poorer spoken language outcomes.

Even though there is a clear need, there are very few programmes of support that could help parents increase hearing aid use with their child, and those that exist do not use the most up to date evidence on how to increase hearing aid use. This means that these programmes of support might not be as effective as they could be.

We therefore aim to develop a programme of support that targets the barriers to consistent hearing aid use with babies faced by families. We will do this within the scientific theory known as 'behaviour change theory', which is about understanding the things that influence what we do (our behaviours), and then providing support to help adapt behaviours to meet goals; in this case, the goal of consistent hearing aid use. The programme of support will be co-developed with parents, Audiologists, Teachers of the Deaf, and Educational Audiologists, building on work already being done with families across the UK.

Approximately one in 1000 infants are born with permanent hearing loss; making it one of the most prevalent chronic conditions in children. Approximately 95% of these children are born to hearing parents who typically choose for their child to use spoken language (regardless of chosen communication route, e.g., bimodal bilingual). Access to speech from early in life is critical to this goal, and any degree of hearing loss places a child at risk of delays in their language development. These delays can have long-term effects on school readiness, later academic achievement, social and emotional development, employment, and mental health.



One key intervention associated with better speech and language outcomes for deaf children (label used here to describe children with any degree of hearing loss) is the early and consistent use of hearing aids. However, hearing aid use in the early years is inconsistent and infants are not wearing their hearing aids as often as they need to for optimal benefits. Moreover, recent work by our team and others suggests caregivers face a number of (potentially modifiable) barriers to consistent hearing aid use with their infants.

Despite the importance of early and consistent amplification, and the potentially modifiable barriers to hearing aid use that parents face, there have been surprisingly few attempts to develop behaviour change interventions that could help parents to increase hearing aid use. Furthermore, intervention attempts that do exist are not theory-driven, and are methodologically limited.

We therefore aim to develop an intervention to map practical solutions to the barriers to consistent hearing aid use and increase use in infants. The intervention will be: 1) developed in line with the Behaviour Change Wheel approach; 2) co-produced with parents and key professionals across education and health; and 3) developed based on current good practice to fit into the existing infrastructure to aid implementation and uptake.