Looking for help ... I record podcasts using a Blue Snowball mic and Garage Band on my Mac. I get good quality except for the fact that there's sometimes an obnoxious buzzing that occurs when a person is talking. The buzzing isn't really noticeable when there's silence between words, but it's definitely audible behind a voice.
I think what's happening is that your Snowball is capable of detecting when someone is speaking and when someone is not. When there is no talking, it is cutting out all sound (using a compressor or a limiter or some such effect) and when you start talking, it lets it back in.
I'd try a couple things. First, disable that limiter or compressor. If you want it, you can run the whole file through at the end, bu I think you'll get better results if you record everything as is up front. Then, I'd use some type of eq to isolate whatever frequency that buzz or hiss is at. Drop that frequency out and you should be good to go.