iStick 40W TC "Ticking" Noise?

[JuicyFlavors]

After using my new istick 40W TC this morning, I noticed a very faint ticking noise when I held the device up to my ear. I read around and saw some people mention an automated sensitivity checker, or something of the sort. Is this normal, or something I should be concerned about?

Thanks!

EDIT TO CONFIRM:

eleaf just sent me an email detailing that this is normal due to a chip regulating the temperature.

This is good to know for those that have the same question regarding the istick 40W TC.