Very cool video, reminds me of those shown in school in the 1960s. Great images of the mainframe workplace. I wonder if smoking was allowed in those rooms? Very well may have been, as bizarre as it would sound today.
Presumably there is no mention of communication because it was a Navy production and was intended for training. I'm pretty sure Bell was still using relays then in the phone system.
My science teacher in '67 obtained a electronics kit for me from Bells Labs that could sound out vowels, one of many kits available. It was a cardboard box with the circuit printed on top and all the parts enclosed. All you had to do was wind the chokes, wire all the parts together according to the picture on top and provide a battery and speaker.