Padded doors

What’s the deal with these padded doors in Russian movies? Here’s the door of the Director’s office in Sluzhebnyiy Roman (Office Romance) a 1977 movie.

And here’s a door to an apartment, in “Moskva slezam ne verit”, a 1979 film. And there are many others to be found. I have questions, assuming these types of doors were found in real life and not just in the movies.

• When did that style of door get started?
• What materials are used?
• Why have padded doors at all?
• Is that still a common style? If not, when did it end?
• Is/was it just a Russian thing, or were those found in other countries as well?

I suppose I could answer some of those questions myself by paying closer attention to the dates of movies I’m watching.