Loud Squeak When Completing Each Mile or During Alert on Bluetooth

I have noticed this too.  It happens whether there is music or not.  It reminds me of a squeaky chain on a swing at a playground. It's consistently the same for me, so I just assume it's what Garmin has decided iit should sound like.  I don't like it, but I'd much rather have them fix the problems with music controls on headphones with version 3.0.

I experience this noise too, it's almost uncomfortable to hear, sounds like a very out of tune whistle. Hopefully it's something Garmin can address with a software update.

Sad to see that your posts are over two years old.  That screech is like chalk on a blackboard.  

I completely agree.
What earphones do you use?
I use Powerbeats Pro and suffering from this noise every time the watch intends to beep.
Interesting if it's earphones dependent or does it happen to everyone?

Found a way to disable the beep tone, which causes the squeaking noise: www8.garmin.com/.../GUID-4FD1E429-DE3B-4A8F-870B-82D8C482B20E.html

I have a FR 945, its been happening for several years.  I've contacted help / support - however nothing was remedied.  It happens through Jaybird, Adidas, Beats and AirPods - headphones.  I would rather not disable the mile indicator and pace, however the whistle, squeak is really hard on the ears, especially in early morning runs.  Garmin please fix this.  Any alert from my watch exhibits that loud squeak.  It really horrible.

Just turn off audio tones in the audio options easy