Typical vs. atypical: Combining auditory Gestalt perception and acoustic analysis of early vocalisations in Rett syndrome.
Odd timbre and rhythm in early babbles can warn of Rett syndrome before motor loss shows up.
01Research in Context
What this study did
Researchers studied one baby girl who later got a Rett syndrome diagnosis.
They played short audio clips of her early babbles and coos to regular listeners.
The team also ran computer tests on pitch, tone, and voice quality.
What they found
More than half of her sounds sounded odd to everyday ears.
The weird notes showed up in timbre, rhythm, and spectral details.
These tiny voice quirks appeared months before doctors saw classic Rett signs.
How this fits with other research
Leaf et al. (2012) first proved that untrained adults can hear the difference between Rett and typical babbles.
The new study adds acoustic numbers to explain why those gut feelings were right.
Kremkow et al. (2022) later counted canonical babbles in a larger group and found the same pattern: babies with Rett simply make fewer of them.
Together the three papers build a timeline: ears notice it, machines measure it, and counts confirm it.
Why it matters
You can start listening during ordinary play. If a baby’s coo sounds flat, nasal, or off-beat, flag the clip and share it with the medical team. Early sound checks cost nothing, need no gear, and may speed referral for genetic testing.
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02At a glance
03Original abstract
BACKGROUND: Early speech-language development of individuals with Rett syndrome (RTT) has been repeatedly characterised by a co-occurrence of apparently typical and atypical vocalisations. AIMS: To describe specific features of this intermittent character of typical versus atypical early RTT-associated vocalisations by combining auditory Gestalt perception and acoustic vocalisation analysis. METHODS AND PROCEDURES: We extracted N = 363 (pre-)linguistic vocalisations from home video recordings of an infant later diagnosed with RTT. In a listening experiment, all vocalisations were assessed for (a)typicality by five experts on early human development. Listeners' auditory concepts of (a)typicality were investigated in context of a comprehensive set of acoustic time-, spectral- and/or energy-related higher-order features extracted from the vocalisations. OUTCOMES AND RESULTS: More than half of the vocalisations were rated as 'atypical' by at least one listener. Atypicality was mainly related to the auditory attribute 'timbre', and to prosodic, spectral, and voice quality features in the acoustic domain. CONCLUSIONS AND IMPLICATIONS: Knowledge gained in our study shall contribute to the generation of an objective model of early vocalisation atypicality. Such a model might be used for increasing caregivers' and healthcare professionals' sensitivity to identify atypical vocalisation patterns, or even for a probabilistic approach to automatically detect RTT based on early vocalisations.
Research in developmental disabilities, 2018 · doi:10.1016/j.ridd.2018.02.019