Python add sound sequence result only one frame import bpy
from bpy import context
import os
print(os.getcwd())
scene = context.scene 
print(scene)
if not scene.sequence_editor:
    scene.sequence_editor_create()
scene.sequence_editor.sequences.new_sound("digital", "~/sound/digtal.mp3", 1, 19)
Problem in invalid file path.

Короче надо так '//digital.mp3', а не '~/sound/digtal.mp3'

scene.sequence_editor.sequences.new_sound("digital", "//digtal.mp3", 1, 19)