New research: Pregnancy lowers the voice

New research: Pregnancy lowers the voice


norman lebrecht

June 02, 2018

From a University of Sussex study:

Over 600 voice recordings were collected from 20 mothers and 20 age-matched controls (“nulliparous” women who had never given birth). Both samples included singers, actresses, journalists and reporters. These voice clips were then acoustically analysed using Praat, a popular open-source acoustic analysis program for measuring human speech.

We found that mothers’ mean and minimum pitch dropped 14 Hz on average (around 1.3 semitones) after pregnancy compared to before. The maximum voice pitch of new mothers dropped as well, by 44 Hz or 2.2 semitones on average, confirming that reaching high frequencies may be particularly challenging for some women in the year following childbirth…

Read on here.


  • Bill says:

    “nulliparous” women who had never given birth

    I didn’t realize there was any other kind of nulliparous woman, Maybe next we can read something about vocalists who sing, and instrumentalists who play.

    • Bruce says:

      “A __[word]__ which is __[definition of word]__”

      This is actually a common way of explaining what a word means, if the writer doesn’t want to resort to parentheses or footnotes.

  • william osborne says:

    I’ve heard so many singers say that pregnancy improves the voice, that it seems like a sort of conventional wisdom.

  • Will E. Coyote says:

    The abstract of this publication (the full paper is behind a paywall) only states that the change in frequency was “significant”, i.e. not due purely to chance.

    But it did not state *exactly how likely* it was that their findings were not random. For example, if the selected significance level was alpha=0.05 (a “sloppy” value) and they found p= 0.049, that means there was as much as 1 chance in 20 that the findings were due to happenstance (for example bad luck in the selection of the study subjects).

    It would also be important to define what a *physically relevant* change in pitch would be for a singer, and whether the study revealed this difference.

  • Sharon says:

    There are numerous hormonal changes during pregnancy which can change the vocal cords. An interesting study, if it has not already been done, is to determine how newborns respond to voices at different pitches

  • Saxon Broken says:

    Umm…technically they found women who have given birth have lower voices than those who have not. So…one explanation is that having a lower voice is more likely to get you pregnant. You need a diff-of-diff estimator to show what they want to show.