I worked for about 6 months before one day there was an emergency announcement over the PA. Before the voice actually came on, the white noise generator cut out

I worked for about 6 months before one day there was an emergency announcement over the PA. Before the voice actually came on, the white noise generator cut out and it was weird. I had always assumed it was a noisy air duct. What you trade off is absolute sound level for attenuating speech like noises faster than they would naturally. So going from nothing to white noise is going to sound and feel noisier. But you will find that you can't hear people talking across the room as well as you could when it was quieter. I consider it a net positive. But then again I also wear headphones frequently to listen to music for focus (and to drown out everything).