Do your brake levers ever buzz/hum?

[MagnumPA]

I just noticed today that when I'm moving, my brake lever was making a buzzing/fast ticking sound, but it doesn't happen if the bike is stopped.  I usually ride with a small USB speaker for my kid on the back, but today I didn't use it so I'm not sure if it has always made the sound, or if it's something that just started happening.  It seemed like the front lever did it every time I used it, and the rear one only did it a few times? It's a Rad Runner Plus, just over a year old. 

[brentc133]

Both our Radrunner +?s do it and always the front brake. I tried cleaning the brake rotor with rubbing alcohol but didn?t make a difference. Next I?m going to check that brake pads are cantered.

[Radiculous]

I get an occasional buzz from the 7speed shifter. A quick flick with my finger and it's gone.