The date is conjectured from the fact that CD was writing on the voice as a means of expression at the end of 1871 (Correspondence vol. 19, letter to H. E. Litchfield, [before 2 December 1871]. Henrietta Emma Litchfield has altered the first question to read ‘& on successive occasions, on approximately the same note’, and the second question to read ‘Do different infants or young children cry on the same note relatively to their usual voice?’. This letter was previously published in Correspondence vol. 20, Expression supplement, from a transcription in a sale catalogue.

CD discussed the pitch of children’s speech in Expression, p. 86, and the possible relationship between the shape of children’s mouths when crying and the sound resulting in Expression, pp. 91–2. CD had circulated a questionnaire about expression from 1867 onwards, but there is no evidence that these questions were circulated. This draft may be connected with the letter to Emily Talbot, 19 July 1881 (Correspondence vol. 29). In that letter, CD suggests that it may be worth investigating uniformity of pitch in the voices of young children under various frames of mind. His letter was published with other items in as section of the Journal of Social Science 15 (1882): 1–52 on infant development. The section concludes with a questionnaire for parents, although it does not include any of the questions CD asks here.