Right sound or wrong sound in this 1957 promotional video?

[blueaircraft]

The video in question:https://www.youtube.com/watch?v=aU6EXdAproc

I want to know in particular what sound does the Britannia at the beginning of the video "uses?" Is it dubbed "accurately" or is another engine used? I'm sure that the engine sounds have been dubbed regardless of accuracy or not, but is that a Proteus engine? Or another type of engine? Feel free to pretend you're one of the people seen in the film regardless

Regards
Andrew

[aeronavesdemexico]

If you are referring to the Britannia at the start taxing, just after the radar rotating... then yes THAT a Proteus at low RPM's

[blueaircraft]

Thank you! I suspected that because the sounds lined up with what I use in FS9.

Regards
Andrew