How can I make smooth audio transitions when editing a video?

Question

I have a video that is essentially one person talking, with a crowd of people listening and responding. What I'd like to be able to do is edit out some sections of the speech.

I need to do this in my video editor, because there are three tracks of video synchronized with the audio.

If I just delete sections and then close the gap, that's obviously going to sound wrong.

But how do I smooth out the transitions? is it a simple fade between tracks? Do I overlap them and fade them? Is there a particular technique for this?

Is there a guideline for how long or short the crossover has to be in order to make them seamless or at least not jarring to the human ear?

Please note I am only concerned about the smoothness of the audio transitions. Where the video cuts are made can be covered with other images.

Also, I am using Kdenlive for my video editing.

Answer 1

There is a technique called 'L cut' and 'J cut' that may be useful to you here. With an L cut you let the audio from the previous clip play over the beginning of the following clip. A J cut is the opposite (audio from the next clip comes in before the vision).

There is no set amount of time for how long a fade or transition should be. It depends on too many factors, the biggest of which being creative choice.

EDIT: I have no experience in Kdenlive, so I'm not sure of its capabilities, but you could give something like this a try:

It's just two crossfades. If they go for long enough the transition should be very smooth. Like I said before though, there is no set time that a fade should go for. You just have to experiment with it and see what works.

If you have a pen tool in Kdenlive you can try fading audio with that. Will give you a lot more control.