This is simple. I think of two methods.

The first method is to record a 3-second blank audio first, which can be recorded using the computer's built-in recording tool. Then merge the first music, blank audio, and second music into one audio in order. For merging here, you can use Beaver Video Converter, which can intercept, merge and convert audio and video into different formats, which is quite convenient.

The second method is to directly import the two audios into the audio editing tool. The first music is placed on the first track, and the second music is placed 3 seconds after the first music. This way There will be 3 seconds of blank time in the middle of playback, and 3 seconds of silence can also be inserted between the two audios. Because the beaver nest method is used, I also saw this there. I hope it can help you.