Do notification sounds use a different speaker than everything else?

[AC Question]

I had to fix my Nexus 6. I changed out the mid-frame as my volume down button got jammed. Since then my notification sounds will not work. It just buzzes once and that is it.

The sounds for making calls, receiving calls, and listening to music all work just fine. Even when I go in and set the sound levels in the sound area of settings, I can hear the phone ringtone just fine, and the alarm ringtone just fine, but notifications make absolutely no sound when I adjust the levels. I can hear them, however, when I have headphones connected, or at least that worked once.

I am wondering if I damaged a speaker or something, and that notifications use a different speaker than call ringtones, alarms, etc. I don't know why else notification sounds would just stop like that, yet everything else works just fine.

On a side note...After I changed out the mid-frame, this problem came about. After that I did root my phone and install LinageOS 14.1. I am still having the same problem though. I just want to be able to hear text, Hangouts, etc. notifications. Any information would be greatly appreciated.