The hypothesis that musicality represents information about the internal mental state of a speaker, together with the hypothesis that musicality is measured across multiple aspects of speech perception, suggests a straightforward test of the theory. Given reasonable plausible candidate formulae for computing different aspects of musicality, apply them to a corpus of "normal" speech, and then calculate the correlation across different aspects.

The concepts in The Statistical Structure of Human Speech Sounds Predicts Musical Universals published in The Journal of Neuroscience can be combined with the theory in my book about calibration of perception of harmonic intervals, to give a fuller picture of how the brain perceives intervals.

Pitch is determined by naturally occurring periodic sounds is another important paper by two of the authors of "Statistical Structure ...". Although of less direct relevance to my own theory, it is significant because it provides strong evidence for the existence of a relationship between music perception and speech perception.

One reason why certain aspects of language, such as phonemes, are not highly relevant to the perception of musicality, may be that those aspects did not exist when the perception of musicality evolved. This suggests that language at that time had melodic and rhythmic aspects, with only one vowel and one consonant. A recent study of the Silbo Gomero language could shed some light on this possibility.

Is there such a thing as animal music? This might seem to be the same question as "Do animals make music?", but there is a subtle difference between the two. Composing good music is not an easy thing even for people to do, so it may be that animal music could exist, but the animals are not clever enough to make it up by themselves. Whereas those animal sounds that sound musical to us may not be musical at all to the animals that make them.