Inputting 2 sound files on 1 sound layer

If you create a sound layer and import a sound file into it. It is possible to input a second sound file into the layer. If you import the 1st file at frame 10, then import another without moving the frame pointer, the second will start at 10 + 1, I.e. frame 11.

This can be used to produce interesting sound effects. But the only way to delete 1 of the sound files is to delete the sound layer and start again, sound wise.