Hi davaid4848,
Welcome to the HP forum!
I understand your audio is choppy and you think it may be hardware. You can test the hardware by running a diagnostics on your computer. About UEFI and the Startup Menu. This will allow you to test the hardware. The sound card is on the motherboard, and that is replaceable. Here is the HP ENVY dv6 Notebook PC Maintenance and Service Guide that provides upgrade or replacement information.
You can run the HP Support Assistant to help resolve errors and update drivers. Have you tried the built in Windows troubleshooter? Did you update your system to Windows 8.1? If it is not hardware and you did not update the Operating System, you can try a system restore, back to a known good time. Please let me know the outcome.