I have the "old school" Naida IIIs which I think have "comfort in noise".
I notice that if I'm talking to someone outside and a loud car or fire truck with sirens blaring passes, the hearing aids suppress all sound for around 20 second. It takes them a while to realize that the sound has passed and that the person I'm talking to is still talking.
This used to happen ALL. THE. TIME. When I worked in an emergency room and I'd be talking to the doctor but a patient in the hall would yell or something and I lost 20 seconds of the conversation.