iPhone 4 audio only works for a few seconds

iPhone 4 audio only works for a few seconds

I've had my iPhone 4 for a long time, and I don't really want to get a new
one. I'm trying to find a solution to fix it. The alert sound, key clicks
and lock sound still work, but sound through the headphones and speakers
only work for a few seconds at a time. I have to press Pause and wait a
few seconds for it to work again.