yes possible speaker issue, to isolate if its speaker or the carrier, transfer the sim on another phone and see if same problem

Sounds like your speaker is shot; Any change with earbud plugged in?
How does is sound when you play music or voice record playback?

From reading, I found out that the popping noise is more likely to be a carrier's issue. If you haven't tried still, try inserting a different SIM and check if it still does it. If the sound is still there do a master reset/security wipe on handheld after backing everything up via Desktop Manager

You may your "minute beeps" turned on. Not sure why others calling you are getting a popping sound. It could be something with the cell tower (cellphone tower). Try a different location where your phone is using a different cell tower.

Hi ,

I have a i776 phone and when I make or receive a call the person Im talking to says they keep hearing a popping sound with nothing being said and i hear what sounds like a beeping noise but not sure. When they are talking, they hear it all the time and I am only getting every other word and sometimes less thaan that. Im at a loss of what it could be. Help please.