Managed to fix it! Found these steps to help
Fix 1
Step 1: Right-click the sound icon in your windows task bar
Step 2: Click 'Sounds' and then 'Playback' tab, select the audio device you are using
Step 3: Click 'Properties' then 'Advanced' and change the 'Default Format' to 32000hz or higher (if you have both 32000hz and 32000hz FM options, select the FM option)
Step 4: Disable 'Exclusive mode', un-tick both of the options
Fix 2
Step 1: Right-click the sound icon in your windows task bar
Step 2: Click 'Sounds' and then 'Playback' tab, select the audio device you are using
Step 3: Verify that the device is the default device (it will say beneath it), if its not you can right click and choose 'Set Default'
Fix 3
Step 1: Within FiveM, press Escape and go to 'FiveM Settings'
Step 2: Click 'Voice Chat'
Step 3: Cycle through the input and output devices and make sure they are set correctly