Vocal toning

I came across an article today on 'vocal toning' during labour, and it mentioned that the long A sound as in "ACE", when said in lower tones and held helped dilate the cervix and create more space within the pelvis.

Janice Clarfield is a Yoga instructor from Vancouver, BC; she has put out a Prenatal Yoga CD set which includes instruction on Visualization, Guided Relaxation, Vocal Toning and Breathing techniques.