Like Mikark, I found the noise really bothersome. And it is very time consuming. On my last visit I asked for hair colouring of light brown. The trainee coloured my hair a jet black. The supervisor agreed it was horrible. And said she was sorry, but there was nothing they could do to lighten it.
That was a two years ago, and I haven't been back.
Nonie, IMHO, you have special hair, and you need an experienced beautician!