In film, the use of in camera audio is a bad move. The quality of the audio can never compare to if it were recorded with a professional microphone in a professional setting. This is where Foley comes into play; the practise of reproducing the audio in a film by overdubbing it in a studio and subsequently mixing it into the edit.
An example of Foley in use.
As you can see, the people in the video simply need to follow the onscreen action with whatever object they can use to recreate the sound you would normally hear. In some cases, you don't even need to use the same object as what is onscreen to make the correct sound, like when the woman slices play-doh to simulate a fish being cut open about 26 seconds into the video.
As long as the audio is put together with the video and mixed correctly, the audience will never realise how the sound is actually made, and the suspension of disbelief will continue.