The message

from D7666 contains these words:

I think they are noisy for what they are, this is from the outside.
They make far more noise passing by than 350s do.

It seems to depend on where you are when they go past you. At Acton
Bridge they're both very noisy when running through at normal speed
(90-ish for the 350 and 120-ish for the Pendo. It also depends on how
many wheel-flats each individual train has...

--
Dave,
Frodsham
http://dave-jackson.fotopic.net