front brake noise

[bluehose2012]

hi, I recently had my front brake pads changed. the brake is working fine.

at times, especially after riding awhile, the front brake lever makes a noise that almost sounds like a duck quack. it doesn't do it every time-and if I let on and off the brake, the noise seems to go away.

I believe my mechanic did everything he was supposed to when changing the pads.

any thoughts? thanks in advance.

the bike is a 2006, with 12,500 miles.