Checking Speech Audibility is Important When Assessing Kids with Mild Bilateral Hearing Loss

Sunday, January 19, 2020

​​​​​​​​​​The ability to hear is directly connected with children’s development of the written and spoken language skills that are essential for many aspects of life. However, there is some confusion and disagreement regarding whether children with mild, bilateral hearing loss should receive hearing aids. Compared to young children with moderate or severe hearing loss, children with mild hearing loss may be able to hear some speech sounds without the use of hearing aids. The impact of mild hearing loss on early speech and language development can be subtle and easy to miss by parents and doctors alike, but without intervention these children may still be at risk for later language delays. Therefore, providing better assessment of the impact of hearing aids for children with mild hearing loss would be a great benefit to families and audiologists who are working to help them.

Ryan McCreery, Ph.D., Director of Research at Boys Town National Research Hospital, and his team have been looking at how amplification, language, and cognition support speech perception in children who are hard of hearing in order to improve outcomes. In a recent paper, Dr. McCreery and colleagues specifically examined the use of a standardized Speech Intelligibility Index (SII) score ^[1], measured without hearing amplification, as a new tool for assessing hearing aid candidacy for children with mild hearing loss^[2]. Their goal was to develop an evidence-based criterion for when children with mild hearing loss would benefit from hearing aids.

The SII uses audiological measurements and takes into account individual ear acoustics to predict a child’s access to speech sounds ^[1]. Children with scores less than 80 on the unaided SII should be consid​ered candidates for amplification because of risks for language problems. This score would correspond to pure tone averages of 20 to 30 dB of hearing loss but is more informative than just measuring dB of hearing loss from the audiogram ^[2].

Another goal of the study was to determine how much hearing loss poses a risk to language development. Dr. McCreery and his team found that children who were able to hear 80% of speech sounds, or less, without hearing aids were at risk of delays in language and vocabulary development, emphasizing the need for more meaningful testing ^[2].

Based on the results from the study, Dr. McCreery and colleagues recommend that clinical audiologists include speech audibility as part of a standard for hearing aid fitting instead of the hearing test. Specifically, the authors found th​at hearing aids could support language development for children with mild hearing loss who hear 80% or less of regular speech sounds. In addition to providing a clear criteria for fitting hearing aids, discussing hearing loss in terms of speech audibility can help families of children with mild hearing loss better understand the benefits of consistent hearing aid use on language development.

The authors’ complete findings can be found in the journal, Language, Speech, and Hearing Services in Schools.

References

1. American National Standards Institute. (1997). American National Standard: Methods for calculation of the speech intelligibility index. Acoustical Society of America.
2. McCreery R.W., Walker E.A., Stiles D.J., Spratford M., et. al. (2020) Audibility-based hearing aid fitting criteria for children with mild bilateral hearing loss. Lang S​peech Hear Serv Sch. 51(1): 55–67. https://doi.org/10.1044/2019_LSHSS-OCHL-19-0021​
   

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