Sound generator filtration question?

[Leejay-b 1]

I test drove a GT86 around a year ago and I'm one of the few who like the sound generator in the cabin, probably because of various loud modified cars in the past.

Looking at the engine bay it appears that the sound generator tube enters the system AFTER the filter. Is there a filter in the pipe somewhere to stop dust etc?

I know it's unlikely and of course when designed this must have been thought about, but am curious!

[Leejay-b 1]

Ps just seen TRD do sound changers which replaces a small plastic pipe for different sound levels. 

The louder versions have foam removed, maybe this is what acts as a filter on standard car, so surely the red kit with no foam isn't great with no protection?

[Gringosteve 213]

The whole thing is a sealed unit. Air does not travel into the cabin from the intake. The intake air vibrates a sealed diaphragm about half way along the pipe which in turn vibrates the air in the cabin