Please have a look at the new file, heat-original.
Let me know if that works or if the collision overlaps with the previous collision.
Do you know this is not sound that will be rendered into a file?
Workaround: Set the playback to the right frame rate (Timeline), limit anything that could slow it down, and do a screen capture (audio only), Quick Time can this, for example. Then match it to the footage.
All the best