Edit- read else where about cleaning the microphone out and now it’s working!

Hi, wonder if anyone can help because I’m going out of my mind with this.

Trying to set up Trueplay on my new Sonos Five, only it won’t complete the tunning due to ‘excessive’ noise in the room even when it’s completely silent.

No matter what I try ( I’ve even tried it with my clothes off! ) I get the same message asking me to reduce the noise. I even tried sticking close to the speaker but that doesn’t work either. 
 

Can anyone offer any advice ?