Sound of crickets

[Phil Biscuit]

Hi all,

Back again with another noise from my engine bay - fantastic. Assuming I couldn't hear it last time because of the grinding noise from my water pump but here we go. So I've noticed a chirping sound - identical to the sound of crickets. I can hear it at idle and also while driving. The only caveat is that the sound completely disappears once I press the clutch pedal. Even with slight pressure on the pedal, the noise disappears. The noise is quite subtle but is definitely there and can be heard inside and outside the car. I have absolutely no issues with the clutch slipping or getting into gear. Any idea what this noise may be? 

[Scarlett Arrow]

I'm thinking clutch release bearing. If replacing, get an Aisin clutch with a genuine Toyota release bearing.