The lines of several characters are heard at the same time, overlapping. It feels less like reading a script and more like overhearing a real conversation. Put the important conversation slightly forward and blend the rest in like background sound.
Crowded scenes such as a party, a meeting or a dinner table, an argument, or variety-show-style chatter. Keep lines that must be understood separate so they don't overlap.
Generate or record the lines separately for each character and overlap them in the edit. For characters talking over others, use a composition where the mouth is less visible, such as from behind or over the shoulder, so a lip-sync mismatch is less noticeable. Push the start time with adelay, lower the volume below the lead's lines with volume, and mix with amix=normalize=0.
Editor instruction: build overlapping dialogue from two separately generated voice clips; start speaker B 1.2 seconds after speaker A begins, while A is still talking, keep A as the main line and lower B to about 60 percent, then mix without auto-normalizing. Command: ffmpeg -i a.wav -i b.wav -filter_complex "[1:a]adelay=1200|1200,volume=0.6[b];[0:a][b]amix=inputs=2:duration=longest:normalize=0[out]" -map "[out]" mix.wav
M*A*S*H (1970) — Overlapping dialogue was a surprising experiment at the time and later became Robert Altman's trademark (Britannica) · Nashville (1975) — In the recording-studio scene right after the opening credits, several people talk at once, each on their own topic (No Film School)
Not verified