Intelligibility of Children’s Speech in Digitized Speech

Abstract

The current investigation examined the intelligibility of digitized speech recorded from typically developing child speakers, ages 4, 5, 6, and 7 years, and reproduced on an augmentative and alternative communication (AAC) device with digitized speech output. The study used a between group design. Forty adults were asked to transcribe 120 words spoken by child speakers in one of the age groups, and presented on an AAC device with digitized speech output. The dependent variable was intelligibility (percent of words correctly identified) of the children’s speech. Overall, the intelligibility of children’s speech increases with the age of the child speaker. However, there was a lot of individual variation in the intelligibility of children’s voices. There was no clear cut-off age, although the speech of some young children may not be sufficiently intelligible on an AAC device that uses digitized speech. Clinicians and parents choosing child speakers for AAC devices with digitized speech are cautioned to carefully consider the speakers used for recording digitized speech output and the characteristics of the speech of the individual speaker. Future research directions are discussed.

Keywords::

• Augmentative and alternative communication (AAC)
• Speech output
• Digitized speech
• Children
• Intelligibility

Acknowledgments

We are grateful to Jaime Catoggio, Lauren Kinley, Barb Roberts, Jacqueline Rowland, Julie Spiker, and Amanda Wertheim for their assistance with data collection. This work was supported by Grant Number 5 R03 DC 006158- 02 from the National Institute on Deafness and Other Communications Disorders (NIDCD), National Institutes of Health (NIH), awarded to the first author. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH.

Declaration of interest: The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.

Appendix

Lists of words used as stimuli (lists were balanced according to the number of syllabi in each word and the the CDI norms for each word)

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