I stumbled across this website and figured it may be of use to someone.
For personal use sounds are free (under the terms of the RemArc Licence) but for commercial use it seems a bit pricey. If you need them for commercial use then I'm unsure if the price is comparable to other sites.
The Sound Effects are BBC copyright, but they may be used for personal, educational or research purposes, as detailed in the license.
These 16,000 BBC Sound Effects are made available by the BBC in WAV format to download for use under the terms of the RemArc Licence.github.com/bbc…pdf
For commercial use, you can license sound effects.blog.prosoundeffects.com/how…ons