Loudness without exhaust: How loud?

Let's ask a (silly?) question:

How loud is a TDI (1Z) engine without an exhaust system?

Background:

Passat 35i
Ich bin jetzt ein paar Wochen ohne Nachschalldämpfer rumgefahren, weil ich zu geizig war, mir einen neuen Topf zu kaufen. Der Klangunterschied war fast gar nicht zu hören, ich hatte mich schon gewundert wozu man so ein Teil dann braucht... NOkay.

The car had been parked at the airport parking lot for two weeks. Then, on the way home, the center muffler also fell off.

Okay: Engine -> Manifold -> Catalytic Converter -> 1.5m pipe.
The car should be making a lot of noise right now, shouldn't it?
It sounds a bit muffled now, but it's not really loud. There's also a hissing/whistling sound, which sounds like the charger. I've never heard my turbo before...

What now? Should I try a normal fuel filter, or could it be that the cat is clogged, as is often mentioned here? I've tapped it, but I don't hear anything rattling inside...

Thank you in advance for reading this!
David.

'Mine also broke after the specified lifespan, and it had a hole in the catalytic converter, etc. But you don't really hear much about that. It's just a bit louder and has a deeper sound, that's all. It definitely doesn't go far enough to get me pulled over by a police officer. (75 HP TD, engine code AAZ).'

Okay, understood. Thank you for the response.

It only worried me because the noise level of both of our 'suckers' is a bit higher when the exhaust is removed.