When it comes to audio in Unity, there are four components: Audio Clip , Audio Source , Audio Listener , and Audio Re-verb Zone . Audio Clips are the actual audio file imported into your game. Unity supports file formats: .aif, .wav, .mp3, and .ogg. When imported, you can compress them greatly, with the price of loosing some quality. You can do this by first selecting the audio clip, view it in the inspector. Under the Audio Importer component, you can switch the audio format from Native to the audio clip, to a compressed format applied by Unity. You can change how compressed the file is by dragging the bar at the bottom, then hitting apply. You can get plenty of free good SFX from a site called freesound.org . All you have to do is create an account for free , and download all the sounds you want. I found a nice gun shot sound here . Simply download and load into your Project. Audio Source actually plays the audio clip in your scen...
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