Between the years 2010 and 2012 my investigations of the relationship between vocal functioning and male puberty led me to record systematically the voices of over one thousand boys. You can read more about how this was done in this document: 1000 Boys Voices Data Base.
The primary motivation for this work is the so-called “secular trend”. “Secular trend” has nothing to do with the abandonment of religion! It refers to a slow drift in a population statistic (e.g. pubertal onset) over a period of time. One of the great frustrations of researching the extent to which the timing of pubertal onset and hence voice change has advanced (as is frequently claimed) is the absence of any reliable baselines. A key purpose for the database was thus to provide such a baseline, albeit for the year 2012. Here is a summary of the main result. SF0 stands for “Speaking Fundamental Frequency” – the habitual mean pitch of the speaking voice:
This table highlights the 2012 regression pattern in relation to Cooksey’s stages (left hand column):
If you are a researcher requiring access to more detailed breakdowns of these data, I will be pleased to oblige.
This figure shows the detailed results of just one boy who was uniquely studied at monthly intervals over a three year period. It shows clearly how a falling SF0 correspond to growth spurts during puberty.
Aside from medical issues, the significance of the secular trend is that if puberty arrives earlier, boys lose their treble voices correspondingly sooner. Part of the database project included a study of seven English cathedral choirs. This was undertaken against a backdrop of press scare stories suggesting that cathedral choirs were under threat because of “voices breaking earlier”. This figure is the result of that study:
It shows that almost the whole of the traditional “top year” for the majority of cathedral choirs had begun puberty, with a little under half the boys at the “completing puberty” stage. In other words, their voices had indeed “broken” (it is more appropriate to say changed. The voices of boys “in-puberty” are changing).
Having a changed voice does not necessarily stop boys from singing soprano (or “treble”). Many continue to do so for some time after completing the main changes of puberty – a fact that has divided opinion amongst singing teachers and created an on-going research topic:
Read new essay: Beautiful Swansongs of English Cathedral Music
Protracted “treble” careers have also greatly muddied the waters concerning the timing of voice change. If boys continue to sing soprano (in a falsetto or quasi-falsetto voice) after puberty, we cannot use historical data on the times boys leave choirs as a valid measure of the timing of puberty.
This work follows in the tradition of John Cooksey. Cooksey’s norms for adolescent male voice change are highly regarded and often cited. However, a problem has arisen concerning the pitch of the unchanged voice. Cooksey gives a mean frequency of 259Hz. Such a mean is found nowhere in my own data. Possible reasons for this have been considered and the most likely is that too few boys of pre-pubertal status are found in my dataset. If this is true, then it follows that by the age of ten a majority of boys must have reached Cooksey’s Stage 1. This points towards a possibly significant advance in the timing of pubertal onset since Cooksey stated this to be between eleven and twelve years of age. Cooksey’s data were gathered between 1979 and 1982.
The major difficulty here is that data on boys aged under eleven do not exist. Cooksey gathered none at all, whilst I gathered data only on a relatively small sample of nine and ten year olds enrolled in cathedral choirs. I am now therefore collaborating with three colleagues to create a further database of boys aged between nine and eleven. This should provide a major advance in knowledge about the timing of puberty and puberty trends.