Dolphin sounds bugs on Resident Evil games.

Do you have a .ISO of the game, I mean did you make a ISO file from a hard copy of the game ?
Some online ISO's are badly compressed and a lot of files are either missing or broken.
What is your system specs, plug-ins your using on the dolphin emulator, have you been updating Dolphin with the most recent
patches and Revised updates ?

P.S - Emulators are very stressful on your computer, I have a monster built gaming rig and even mine sometimes have slow downs within emulators.
To be honest they are never as good as the real hardware and never really will be and you will also come across some problems.

Your spec's should maybe be fine.
I would suggest your CPU being over 3.0ghz but it should be fine if the emulators running with no hitches.
My CPU is running at 4.1ghz and still has glitches in emulators so I'm guessing there just stressful to run.
I would suggest try a different ISO of game, might be the copy that you have that's been badly compressed.
I would also make sure that if its a US copy then make your BIOS US etc.
Use the standard audio, I do and dont get any sort of glitches, although REmake is like missing some instruments and tones in the BGM's.
I used the hard copy and it was still the same so I'm guessing it's just the emulator.
I updated to the latest patch and latest revised patch as they get updated regular and fix a lot of bugs, they will also sometime offer game fixes which people have complained about.

I can only really suggest going back to default sound plug-in and updating.
You can find the newest update on Dolphin's official site.