Thanks restoresleep and bernieb for your replies. My husband's machine is also only a few months old and i would say the noise has been present from the start. I will contact Resmed here in Australia where we purchased it from

Hi Restoresleep, this noise on inhalation you have attached to your message is identical to the noise we are getting from my husband's machine. He had a trial machine previously and it was quiet but since owning this brand new machine it is very noisy each night. We too have checked out a few connec...

Ohh this is exactly the noise of my husband's machine. Every inhalation is heard. It sounds as though the noise is coming from the machine itself near where the hose connects to it. Did you work out what the problem was? Thankyou