At the age of about four months the baby starts babbling and producing different sounds.
Interestingly, during the first six months infants with ASD show a similar to typically developing infants’ rate of vocalizations, the pattern of face-gazing accompanied by vocalizations (Young et al. 2009) and typical behaviour in social-vocal patterns (Chericoni et al. 2016). (At this age, the first signs could be looked for in other areas, such as, for example, motor development, which shows atypicalities starting from the first months of life or in the acoustic characteristics of infant’s cries, and atypical auditory processing.)
However, from 6 to 12 months infants later diagnosed with ASD produce significantly fewer vocalizations and show a distinctive pattern of early pre-linguistic vocal behaviours: after an initial regular display of vocalizations at 6-12 months there is a decrease in vocalizations in babies with autism, as opposed to the increase found in typically developing infants (Chericoni et al. 2016). Young children with ASD demonstrate a strong association between vocalizations and expressive language skills. The quality of vocalizations can predict later expressive language skills in young children with ASD (McDaniel et al. 2020).
At the age of about four months the baby starts babbling and producing different sounds. Between six and ten months, babies start to produce simple syllables (a consonant + a vowel) in a repetitive way, for example, ‘ba-ba-ba-ba-ba’. After vocalisation, reduplicated babbling is the most important milestone in the first year of life (Iverson et al. 2007), and later two syllables babbling develops. It is difficult to establish the purpose of babbling and its connection to word structure. It has been suggested that babbling reflects the biological maturation of the central nervous system as it doesn’t seem to depend on external reinforcement – deaf children babble at the same age as hearing children.
Interestingly, that the amount of babbling doesn’t distinguish the autistic and typically developing infants. However, in autism solitary babbling is more prolonged than in typical development, as opposed to interactive babbling which is less frequent. It appears that these two kinds of babbling have different developmental functions: the function of solitary babbling is to explore sensorial variations, whereas during interactive babbling babies are taking part in a conversation with a social partner (Konopczinsky 2010).
Babbling increases progressively both in autistic and typically developing infants. However, at 12-18 months 2-syllable babbling is less likely to be accompanied by face-gazing in toddlers with ASD, as opposed to the babbling pattern with face-gazing in typically developing children. After the first birthday, the delay in first words distinguish toddlers with ASD from their typically developing peers.
At about ten months the baby seems to discover that sound is connected to meaning and babbling becomes more consistent; the baby produces certain sounds and intonational patterns to refer to different objects and events. The process is often referred to as ‘jargon babbling’. At the end of this period, infants start producing ‘protowords’ – invented or derived forms used in specific situations. It is interesting to note that ‘gestural babbling’ has been reported by the researchers studying the development of deaf children (Petitto et al. 2000). The discovery of babbling in another modality confirms the hypothesis that babbling represents a distinct and critical stage in the language acquisition.
The research (Petitto et al. 2001) shows that by interpreting the baby mouth motion during babbling, it might be possible to diagnose language/ communication problems/ disorders already at this stage of a child’s development (as early as 5 to 12 months) and start early support. It depends upon which side of the mouth babies open more widely. As language is linked to the left hemisphere and smiles to the right hemisphere’s emotional centres, researchers claim that if the babies open the right side of the mouth wider than the left side (‘right-mouth asymmetry’) it means that the language centre in the brain is active, if the babies’ mouths open more on the left side during babbling, then there might be problems with language acquisition.
‘Speaking’ a different language
The vocalisations of older non-verbal autistic children remain idiosyncratic. In some very interesting research (Ricks 1979) the expressiveness of the vocalisations of non-verbal autistic children (between three and five years old), non-verbal intellectually disabled children and eight-month-old typically developing children was compared. All the children were presented with stimuli designed to elicit different emotional states (surprise, pleasure, frustration, need). All the children’s vocalisations were recorded and then presented to the children’s parents to ‘interpret’.
The results showed that all the parents could match the vocalisations of the intellectually disabled and typically developing children with the correct emotional state, though the parents of intellectually disabled and typically developing children failed to identify their own offspring. In contrast, the parents of autistic children could not only match their child’s vocalisations with the emotions expressed but also recognise their child; however, they couldn’t interpret the vocalisations of other autistic children. These results were interpreted as the vocalisations of autistic children being expressive but idiosyncratic: they were meaningful only for their parents and not for other people.
Could we consider these results as that autistic children ‘speak a different language’ understood only by their parents who, after years living together, have learned (intuitively) the ‘language’ their children ‘speak’?
We were talking in the kitchen of a one-room flat. All of a sudden Tanya, the mother of a six-year-old non-verbal autistic boy, rushed out of the kitchen into the room where her son was watching TV. ‘He is in trouble’, she said. And she was right: the boy was stuck between the TV set and the wall with a screwdriver in his hand. How could she know this? Andrew’s ‘vocabulary’ was not large: he was able to produce very few sounds and his ‘favourite’ was ‘ah-ah’. As he was ‘ah-ah’ing’ most of the time, how ‘word’ seems to be polysemantic and could mean anything. How did his mother know all the meanings he applied to it?