Mechanism for speech delay in ASD

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My daughter is fairly typical of many ASD diagnosed children in having a speech delay. Through observation it was clear that in the period of her life she was not displaying expressive speech her threshold for external noise was very poor (i.e. Drills, lawnmowers, vacuum cleaners) and she was easily distracted by ambient sounds such as cars in the distance and even bird noises.

By the age of 5 she started regularly using expressive language and coincidentally her threshold for loud noise was much higher. She was nowhere near as distracted by outside sounds, her focus in learning language, words and sentences was dramatically improved.

I was curious as to the neurological basis for this developmental change and came across a principle in cognitive neurobiology called concurrent articulation. According to this principle children have a working memory system (as do adults) where the central executive of the brain shifts short-term storage of numbers and words in sequence using an articulatory rehearsal loop to the inner ear where the phonological buffer allows temporary storage of this data till it is either used by the central executive or moved to longer term storage.

This short term storage can be disrupted by the introduction of external sounds that diverts or distracts the central executive of the brain thus disrupting the articulatory rehearsal loop and preventing short term storage of the data the brain was supposed to be focussing on because it was absorbed on the concurrent articulation of the alternative sound.

I was wondering if ASD children have a problem filtering out extraneous noise and thus this disrupts their working memory from taking up relevant data by being diverted by concurrent noises thus resulting (via some complex mechanism) in a inability to use speech as the inner ear did not have the chance to absorb the subvocal speech the child was listening to?

So, you think the child doesn't learn speech due to tuning it out and focusing on random noises in the environment, like, birds chirping, cars honking, people roller skating, and other ambient noises, or just noises in general, due to lack of filtration. That's an interesting idea.
Maybe someone talking is just one sound among many and it's a lush soundscape to the child, difficult to differentiate the speech alone.

Mechanism for speech delay in ASD. Words: Central auditory processing disorder (CAPD/APD), petit/absence/TLE/complex partial and so on, ADHD Inattentive, working memory/short term memory, filtering sounds, reticular formation of the brainstem - surrounding areas, etc. One educational book which I recall that goes extensively into the complex neurology of auditory processing is the How To (understand) Hyperactivity book (1981) about ADHD Inattentive / central auditory processing disorder / mild dyspraxia by C. Thomas Wild. Wild reports several FDA approved medicines (Tirend, NoDoz) which temporarily improved small aspects of hearing and understanding (not a cure). The How To book can provide insights here and there into the topic of hearing, understanding, and speech (again, no cures at all). More words: ear protectors, ear muffs, etc.