[broadgage]

I saw records for that speed at my old school, and yes they were used for teaching foreign languages. IIRC they were no longer used at that school in the mid 1970s, but may have been used not long before.

I have also heard, but can not substantiate, that they were used for long playing but basic quality background music in shops and workplaces.

I believe that a unit was available that played a record over a PA system, and then when the record finished, automatically reverted to playing a radio broadcast over the same system.
Popular during the war in factories. Entertainment from a suitable record, followed by the war news via radio.
I don't know what RPM records were used in these systems, but 16 sounds likely for a long playing, lo-fi system.

Long after feature films had optical or magnetic sound as an integral part of the film, cinema newsreels did not.
Newsreels were not of course shown in silence, but the sound came on a "special" record that was distributed with the film and played in the cinema.
Would these "special" records have been 16 RPM ?