Internal Speaker does not play sound - click or beep

I have an iPod classic 6th generation 160 GB.

Does anyone know where the internal speaker is located? What might stop it from working? How to fix?

I know that it is not really a speaker, but Apple does refer to it in their manual as an "internal speaker." I am aware that the only sound it is able to emit is the scroll wheel clicking noise and the beep from the alarm clock.

I replaced the back of this iPod, the battery and the cable that connects the hold button and headphone jack. Everything else works perfectly. Any help is appreciated. No one seems to have any info on this issue.