According to Neural Complexity Hypothesis (Samson et al., 2006), as the complexity of the sound and cognitive demands increase, so do processing challenges and their corresponding neurological indicators such as a decrease in blood flow in the auditory associative cortex or reduced activity in the region of the brain associated with word processing (posterior part of the left middle temporal gyrus) (Samson et al., 2006).

O’Connor (2012) suggested that the relationship between superior pitch discernment in non-speech sounds and increased likelihood of speech delay (in some individuals) may be due to “reduced attention to linguistic information” during development, or hypersensitivity to sound that impacts the processing of linguistic information. (2009) found that for autistic adolescents, pitch discrimination was correlated with a higher likelihood of language delay. Despite autistic children’s advantage around identifying and recalling pure tones, this strength does not generalize to speech sounds.

Autism and flat affect