RoutingErrors Showing Up in Production Log

I am seeing errors of this type:

ActionController::RoutingError (Recognition failed for
“/blah/50112.mp3”):

Showing up in production.log. I’d like to suppress as they are ‘known’
and
not real errors.

I have my logging set to:

config.log_level = :error

In environmnent.rb.

What can I do to remove these errors from my log?

Cheers