I've used https://epicstockmedia.com/ a lot and was very impressed with their selection and quality. https://audiojungle.net/ is pretty good too, the only issue there is that it's harder to find sounds that are part of the same collection. Source: about 1 year ago

Https://audiojungle.net/ is a popular site for stock music. You can download anything for free on there, but it will say “audio jungle” every 5 to 10 until you pay for the licensed file where it’s removed. Source: about 1 year ago

On the site audiojungle.net, there's a scream called "Female Scream by WisanSound in Human Sounds" with a green gem as an icon on the side. The download is labled "18676189_female-scream_by_wistansound_preview." No idea where the scream came from, but it's one of at least 3 popular ones I notice. Source: over 1 year ago

This is all trailer music. You may not be able to find the exact ones but you can find hundreds and thousands that are all just about the same on sites like https://www.shockwave-sound.com/ and https://audiojungle.net/. Source: over 1 year ago

Finding the right background music is never easy and you must pay attention on the royalty for the music. This is the reason why very often I use Audiojungle. It's another Envato store but it's full of good music and sounds. Prices are very low and starting from 1$ you can have a good quality. I totally recommend it. - Source: dev.to / over 1 year ago

You might get in contact with a nearby university, professor or student organization that have relevant courses to get in contact with students or alumnis. Other sources for co-founders are startup related meetups or websites (e.g., founders-nation.com). Source: over 2 years ago