Acoustic Change Complex and Visually Reinforced Infant Speech Discrimination Measures of Vowel Contrast Detection.
Barbara K Cone, Spencer Smith, Diane E Cheek Smith
PMID 34456301WHAT IT FOUND
The Acoustic Change Complex (ACC) reliably detected vowel changes in infants under one year old, even when behavioral tests failed.
Presenting sounds at a fast rate (2 per second) yielded accurate neural responses in over 90% of infants tested. This offers a potential objective measure for speech discrimination in young children.
Key findings
01ACC responses were present in over 90% of infants when vowel contrasts were presented at a rate of 2 per second.
02The ACC amplitude ratio metric identified vowel discrimination in many infants who could not meet the training or validity criteria for behavioral visually-reinforced tests.
03Behavioral tests (VRISD) had high failure rates, with only 53% of tests meeting standard validity criteria due to infants' difficulty with the task.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The study was conducted on typically developing infants with normal hearing, so its direct application to infants with hearing loss or auditory neuropathy requires further investigation. The behavioral test (VRISD) had a high failure rate, with many infants unable to meet training criteria, which limits the ability to directly compare ACC and behavioral results for every subject. The study used synthesized vowel tokens rather than natural speech, which may have less spectral complexity and salience than real-world speech sounds. Only a limited number of averages (50) were used for the ACC recordings to mimic clinical conditions, which may have increased variability compared to laboratory settings with longer test times.
Declared interests
The authors declared no known conflicts of interest. The research was supported by the N.I.H. (Extramural).
The easy way to misread this
Do not assume this test is currently available for clinical use with infants who have hearing loss. This study was performed on infants with normal hearing to validate the method; the authors explicitly state that further investigation is needed to determine its feasibility and effectiveness in clinical settings for children with hearing loss.