Auditory brainstem responses in childhood psychosis.

Doctors gave autistic kids a 10-minute hearing test called ABR. The test plays clicks and measures how fast the sound travels up the brainstem.

They also noted which kids had floppy muscle tone and which had almost no words.

One out of every three autistic kids showed a slow or weak brain-stem reply.

Those same kids were also the ones with low tone and big language delays.

The rest of the group had normal ABRs, just like typical children.

Chen et al. (2019) followed preschoolers for almost a year. Typical kids kept steady ABRs, while autistic kids showed faster but smaller waves, hinting the brain-stem path keeps maturing differently.

Santos et al. (2017) looked at wave I size in toddlers. About one-third of autistic tots had extra-large wave I, matching the one-third odd ABR rate seen here.

Spates et al. (2013) used a different ear-muscle test and still found sluggish timing. Together these papers say the brain-stem sound route is often off track in autism, not just in one lab or one decade.

You can run an ABR in any audiology clinic. If the trace looks odd and the child also has low tone, treat language goals as high priority and add auditory processing supports. Share the print-out with speech and OT so everyone sees the same red flag.