I have come across purely mechanical reasons that explain why children have piping/high pitched voices - length of trachea etc. However, I find myself wondering whether there isn't a deeper evolutionary reason why the mechanics evolved that way. Is there a Kinderschema type explanation for this? I have attempted to find information on the subject and turned up nothing - perhaps because I am simply not searching for the right thing.

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    $\begingroup$ While I am not aware of any such theories, and personally would find it hard to follow the reasoning of any such evolutionary argument. I would however suggest it pretty easy to argue the evolutionary benefit that we adult care givers consider 'cute' the vocal characteristics our offspring are capable of producing. So any evolution in my view is likely to be in the ears and minds of the parent instead of the vocal tract of the infant. $\endgroup$
    – norlesh
    Commented Jan 10, 2019 at 19:29

2 Answers 2


Children have high pitched voices relative to adults because their vocal folds are shorter and physics demands that short vocal folds result in higher pitches. The format frequencies of children are also higher than adults due to shorter vocal tract lengths.

I think your question is, is there a speech communication reason for the vocal folds and vocal tract of children to be shorter than adults to which I would argue that it is unlikely. While it is possible to be grown with adult sized features (e.g., the inner ear and the middle ear ossicles), generally babies are smaller than adults. There would need to be a strong evolutionary advantage to being born with a really long vocal tract. Second, from what I can piece together, (e.g., this article) a shorter vocal tract is desirable for suckling. Therefore I would conclude that evolutionary speaking babies have shorter vocal tracts because they are smaller than adults and if the vocal tract was longer it would make it harder to feed.


High pitch sound is a shortwave vibration which travels longer distances than the low pitch sound. It also requires less energy to be produced. So it makes sense that children are able to scream long and loud enough to ask for help.

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    $\begingroup$ Your answer has an intuitive appeal to it. Could you quote a reference or two to the claim that high pitch sounds require less energy to produce etc? $\endgroup$
    – DroidOS
    Commented Feb 10, 2019 at 10:07
  • $\begingroup$ I dont think frequency is related to the energy requirements. Low frequency sounds tend to travel further than high frequency sounds, and maybe that is an evolutionary advantage in that a child can cry loudly for its mother and the sound will not propagate as far alerting predators. $\endgroup$
    – StrongBad
    Commented Mar 12, 2019 at 13:41
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    $\begingroup$ -1 "In general, low frequency waves travel further than high frequency waves because there is less energy transferred to the medium.". There goes this theory. 😉 $\endgroup$
    – Steven Jeuris
    Commented Mar 13, 2019 at 17:10
  • $\begingroup$ I have a question for you: If low-frequency waves require less energy to transmit, then why is it almost impossible for adults to produce the same screeching high pitched noise? $\endgroup$ Commented Mar 13, 2019 at 18:09
  • $\begingroup$ @Palomi Because 'produce' and 'transfer in medium' are not the same thing. I would imagine due to the difference in vocal cord lengths, but I do not know the exact biology behind how sound is produced. Look it up? $\endgroup$
    – Steven Jeuris
    Commented Mar 13, 2019 at 19:37

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