I noticed a specific, unique vocal sound used in several beach boys.
Gonna hustle you: “Do ron day ron day do ron day ron day…” This is an example of it being used quite overtly.
Sometimes it’s used more subtly.
Wouldn’t It Be Nice:
1:10 - “Maybe if we think and wish and hope and pray it might come true…ron ron ooooooo”
And of course…there is the famous work by the Crystals - Da Doo Ron Ron.
Where did this vocalization originate? Does it have some basis in some kind of earlier music, or was it invented in the 1960s?
Ray Conniff and his female singers did that in the mid 50’s. His singers didn’t use actual word. They used sounds. Like you’d do scales, do, rae, me, fa etc…
Later in the 60’s the Ray Conniff singers were allowed to sing popular songs.
I don’t know if Conniff invented it, but it was a big part of his early music. I have most of Coniff’s albums on vinyl.
Ray Conniff singers
they start about halfway in. la, la,la no words
This was Ray’s signature music.
They are using sounds from the scales. do, re /day etc. I guess ron fit nicely with the notes too. 
It was invented in 1960, in Rio, by Duron Duron.
