These audio clips are from Unity Technology's 3D Game Kit, available for free on the Unity Asset Store here:
https://assetstore.unity.com/packages/templates/tutorials/3d-game-kit-115747#content

These clips are used for asset demonstration purposes, as stated in the Publishing Guidelines here:
https://support.unity.com/hc/en-us/articles/206336915-Can-I-submit-an-asset-that-uses-Unity-Standard-Assets

NOTE: I have included both .ogg and .wav formats of each sound file, as recommended by the Unity Asset Store Uploader.