BWP, perhaps if you had read Ina May Gaskin's Guide To Childbirth (available in all good bookstores for £12.00) you would have had an idyllic birth every time:
'Women who grimace and clench their jaws while pushing have a greater tendency to tear, because their perineal tissues are more rigid...'
On making the right noises:
'..not every woman is a professional singer, but everyone can find something to sing while having a baby. Singing will maximise the ability of the body's sphincters to open' 
'..I have often demonstrated the sounds that help dilation: low-pitched moaning and orgasmic sighs' 
'Breast stimulation is especially effective in starting labour at term when it is combined with sexual intercourse. Unless your partner is an abysmally poor lover [!!], this combination is by far the most enjoyable method of induction..'
She goes on to say she encourages her ladies to let their menfolk suck their tits during labour. I fucking kid you not. And, finally..
'Some women like to stimulate their clitoris as the baby emerges...low, sexy moans are good, they vibrate the lower part of the body'
Stick that in your birth plan 