What caused broadcasts to have that “vintage” sound in the mid 20th century

Question

Not talking about the static, mainly the voices of people.

Examples:

https://youtu.be/yYAw79386WI?si=SKCkEeHFLn83ixCB (skip to 4:30)

And a final example of a modern recreation

In: Technology

Answer 1

Due to technology limitations, very low and very high-pitched sounds didn’t get recorded very well—or at all—before the 1950s. Part of what gives a voice its tone is those pitches.

Also, in the old days, many performers were trained to vocalize a certain way and to use a sort of nasal, posh accent which carried well and remained easy to understand in large venues or in lo-fi recordings. Presenters and narrators often used this “standard” public-speaking voice because it sounded authoritative.