For arbitrary ambient sounds, http://www.ambient-mixer.com/ http://www.ambient-mixer.com/ is great. You can create your own mixes or just listen to premade ones

For arbitrary ambient sounds, http://www.ambient-mixer.com/ http://www.ambient-mixer.com/ is great. You can create your own mixes or just listen to premade ones. And you can individually adjust each 'effect' on mix board: http://weather.ambient-mixer.com/light-thunderstorm http://weather.ambient-mixer.com/light-thunderstorm