Hi Michael,
Use Sony’s play memories software that came with te camera to import the clips instead of reading the clips directly from the memory cards in your computer.
When you import your files directly from the memorycards the clips are split into multiple files. Sometimes audio is lost for a short duration on the boundary of two clips.
Importing longer clips with Play memories software will show only one clip when you make a recording of one hour for example.
Hope this will fix your problem.
Best regards,
Arnoud