As universal newborn hearing screening programs identify the presence of hearing loss at birth, audiologists are tasked with fitting and verifying hearing aids within the first few months of a child's life. Audiologists are responsible for knowing how and when to use unique best practice methods for ensuring that young children have optimal access to speech with hearing devices. The hearing aid verification method influences the amount of auditory access children have to language input. Consistent access to language input through hearing aids relates to better speech and language development for children (Tomblin et al., 2015). Using recommended best practices for hearing aid fitting and verification will support children in achieving speech and language development similar to their normal-hearing peers. The purpose of this section is to review best practice fitting and verification strategies that account for the special needs of infants and young children.
Infants and young children are not able to tell audiologists what they are able to hear with hearing aids. Pediatric hearing aid fitting formulae guide audiologists in how to set the hearing aids so that the child has appropriate access to, or audibility of, speech while not making sounds too loud. Two such fitting formulae, Desired Sensation Level (DSL) and National Acoustic Laboratories (NAL), provide a "prescription" for hearing aid output based on a child's age and hearing thresholds. Prescriptive formulae provide targets for the hearing aid output that can be used to optimize audibility of speech at multiple input levels (soft, conversational, loud). Targets for maximum power output are also provided to ensure that the hearing aid does not exceed loudness comfort levels. See McCreery and Walker (2017) for a discussion of the differences between the DSL and NAL fitting methods. Unlike manufacturers' proprietary fitting strategies, prescriptive strategies like DSL and NAL have been validated for use in pediatric hearing aid fittings and are considered best practice (American Academy of Audiology, 2013).
American Academy of Audiology. (2013). Clinical Practice Guidelines on Pediatric Amplification. Retrieved from www.audiology.org
McCreery, R. W., & Walker, E. A. (2017). Pediatric Amplification: Enhancing Auditory Access. In. San Diego, CA: Plural Publishing.
Tomblin, J. B., Harrison, M., Ambrose, S. E., Walker, E. A., Oleson, J. J., & Moeller, M. P. (2015). Language Outcomes in Young Children with Mild to Severe Hearing Loss. Ear Hear, 36 Suppl 1, 76s-91s. doi:10.1097/aud.0000000000000219