Audio output issue

For some reason, the sound is going in and out on my computer. The left speaker is making an odd noise (a clicking/snapping noise) and whenever I try playing a sound it is playing the sound broken up. The output volume under sound when I go to the system preferences keeps saying the output is at a certain level, but then it says "the selected device has no output controls". It switches between the two every few seconds. It can't be strictly a problem with the speakers because when I plug my headphones in it does the same thing. Is something internally wrong with my computer? Do I need to bring it into a store to get fixed? I have the original Macbook Pro. The computer is over three years old. Is the lifespan just nearly up for this computer?

It does appear to be a hardware problem. Possibly the logic board itself regarding the audio. Run the Apple Hardware Test on the machine to see if it shows you anything definitive. Sometimes it will, other times it won't.

Apple Hardware Test

Since your machine is no longer in warranty, you might think about using one of the lesser expensive repair services that are available. There are several which are authorized Apple service repair facilities and maintain a presence on line.

Here's one.

Regards.