Question: What year did studios stop using certain audio formats?

[rinrinabis]

What year did studios stop using Mono?

What Year did studios stop using Dolby Stereo?

This thread is so that I can see when studios stopped using certain audio formats so I can see if an audio mix on a home video release is the theatrical mix or a remix.

[stwd4nder2]

Depends on the specific film. Many films stuck with mono long into the Dolby Stereo era because it was cheaper.There's not a hard cut off.