Mild hearing loss and speech: What new research reveals

When a child has mild hearing loss, it is easy to assume that they will adapt or find ways to manage on their own. While some children with mild hearing loss adapt well, others may face difficulties. The impact of mild hearing loss can be significant, with difficulties shown across physical and psychosocial health, school functioning and language outcomes.

One area that has received less attention is speech production. This analysis from the Longitudinal Outcomes of Children with Hearing Impairment (LOCHI) study explored whether speech production is also an area of concern for children with mild bilateral hearing loss.

Why speech production matters

Producing clear speech is important because poor speech skills can make it more difficult for children to communicate, leading to communication breakdowns that impact peer relationships and the child’s social and emotional wellbeing.

The association between hearing abilities and speech production is well known in children with significant degrees of hearing loss, so we were keen to explore whether this is an area of concern for children with mild hearing loss as well.

About the study
The LOCHI study follows children with hearing loss over time to better understand their developmental outcomes. For this analysis, we compared the speech production skills of 28 five-year-old children with mild bilateral hearing loss who used hearing aids with 60 peers with typical hearing.

Most children with hearing loss were fitted with hearing aids early, with an average fitting age of 13 months, and many wore their devices consistently throughout the day. We examined both the accuracy of speech sound production and the types of speech errors they were making.

Key findings

Speech challenges persisted despite mild hearing loss

Despite early hearing aid fitting and intervention, children with mild bilateral hearing loss showed lower speech production accuracy than their peers with typical hearing.

On average, children with mild hearing loss achieved 76% consonants correct, compared with 91% among children with typical hearing. Differences were also observed for vowel production and overall speech sound accuracy.

Importantly, there was considerable variation within the mild hearing loss group, suggesting that mild hearing loss does not affect all children in the same way and highlighting the importance of individual monitoring.

Certain speech sounds were more difficult

Children with mild hearing loss were more likely to have difficulty producing several speech sounds accurately, particularly sounds such as “s,” “z,” “v” and “ch.”

Importantly, the children also showed more difficulty producing some early-developing speech sounds, suggesting that the effects of hearing loss may extend beyond the sounds traditionally considered challenging.

Delayed speech patterns were more common

We also examined phonological processes, which are predictable speech simplifications that typically disappear as children mature.

Compared with their peers with typical hearing, children with mild hearing loss were significantly more likely to use processes such as:

• Cluster reduction (for example, saying “pane” instead of “plane”)
• Final consonant deletion (for example, saying “she” instead of “sheep”)
• Stopping (for example, saying “pish” instead of “fish”)
• Voicing errors (for example, saying “big” instead of “pig”)

Most of the differences reflected delayed developmental patterns rather than atypical speech errors, suggesting that many children may respond well to targeted speech-language intervention.

Earlier hearing aid fitting was not associated with better speech outcomes

The average age of first hearing aid fitting in this group was 13 months, with children fitted as early as one month of age.

We found no significant relationship between the age at which hearing aids were first fitted and speech production accuracy at five years of age.

While hearing aids remain an essential part of intervention, these findings indicate that early fitting alone may not fully explain speech outcomes in children with mild bilateral hearing loss. Ongoing monitoring and speech-language support may also play an important role.

What this means for clinicians

These findings highlight the importance of continuing to monitor speech development in children with mild bilateral hearing loss, even when hearing aids are fitted early.

Hearing aid fitting alone does not guarantee age-appropriate speech production. Regular monitoring of speech, language, listening and hearing outcomes remains important throughout the preschool years to help identify children who may benefit from additional support.

We invite you to read the publication: https://pubmed.ncbi.nlm.nih.gov/42043911/

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Authors:

Emi Vella, Speech Pathologist, Australia

Emi Vella is a Speech Pathologist committed to improving communication outcomes for children through research. Her work focuses on speech production and developmental outcomes in children with hearing loss, using data from the Longitudinal Outcomes of Children with Hearing Impairment (LOCHI) study.

Viji Easwar, Head of the Paediatric Hearing Research Program at the National Acoustic Laboratories, Sydney, Australia.

Viji Easwar is an audiologist by training and completed her Bachelor’s degree in Audiology in India, Master’s in Audiology at the University of Southampton (UK), and a PhD at the National Centre for Audiology in Canada. Viji’s research focuses on developing clinical tools, including EEG-based measures, to evaluate and optimize hearing outcomes children with hearing loss.