We have used our machine for ~6 years now and recently my wife said she could hear some noise. Being hard of hearing myself I could not, so she recorded the noise with an IPod that playback made with the TV muted.
I could best describe the noise as like a lowish level sizzle,or slight breeze.
I realise that perhaps the method used may not be that good, but could it be a sign that something is wearing out?