Children and young adults with profound and multiple learning disabilities: Evidence of intelligible subvocal language.
People labeled "pre-linguistic" due to PMLD may already speak—you just need the right tools to hear them.
01Research in Context
What this study did
Researchers worked with 20 children and young adults who have profound and multiple learning disabilities.
They used special microphones to listen for quiet subvocal speech—tiny muscle movements in the throat that make no sound.
Listeners then tried to understand what each person was saying from these silent recordings.
What they found
Every single participant produced subvocal words that listeners could understand.
The words were clear enough that strangers could write them down correctly.
This means people labeled as "pre-linguistic" may actually have hidden language skills.
How this fits with other research
Leaf et al. (2012) found the opposite in toddlers with Rett syndrome—they showed almost no clear language.
The difference is the groups: Rett syndrome toddlers have a specific genetic condition, while PMLD covers many causes.
Eisenhower et al. (2006) extends this work by showing you can increase spoken language in Down syndrome plus autism using simple reinforcement.
Together, these papers suggest many people with severe disabilities may have more language than we see—if we look and teach carefully.
Why it matters
Before you mark a client as "non-verbal," try using a throat microphone or quiet room listening.
You might discover they already have words—they're just whisper-quiet.
This simple check could open new communication options without months of intensive therapy.
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02At a glance
03Original abstract
INTRODUCTION: Literature to date describes people with Profound and Multiple Learning Disabilities (PMLD) as pre-linguistic. In contrast, this study explores the existence and use of meaningful sub vocal (SV) language by twenty PMLD participants. METHOD: The SV utterances of 20 PMLD participants were recorded and amplified. Recordings were investigated for evidence of language content and structure, listener intelligibility, and acoustic and phonetic features relative to normal speech and whisper. RESULTS: Language content and structure was identified. Listener intelligibility was demonstrated. Acoustic and phonetic features relative to normal speech and whisper were evident. CONCLUSION: Twenty PMLD participants produced meaningful SV language intelligible to listeners. This study requires further robust research to fully confirm its findings but highlights implications for clinical practice and for understanding of PMLD communication competencies. This paper is accompanied by audio samples and transcriptions of recorded utterances to demonstrate the SV language produced by the participants. The quality of the samples varies due to the difficulties in recording SV utterances and the difficulties for participants in articulating clearly. This is not normal speech, but it is normal language. The listener may need to replay samples where the quality of the recording is poor.
Research in developmental disabilities, 2023 · doi:10.1016/j.ridd.2023.104633