Margaret Thatcher voice before/after

Under the guidance of a tutor from the National Theatre, she [Margaret Thatcher] underwent a training programme which included special humming exercises aimed at lowering the pitch level at which she formwely spoke. From tape recordings of speeches made before and after receiving tuition a marked difference can be very hear. When there are played through an electronic pitch analyser, it emerges that she achieved a reduction in pitch of 46 Hz, a figure which is almost half the average difference in pitch between male and female voices. (Atkinson, 1984, ) from Anne Carson - The Gender of Sound (Glass, Irony and God)