The first ABR tests for my son were done entirely with broadband frequency "clicks" that range from 1000-4000 Hz, roughly the entire speech range. Those showed that our son could hear down to about 35dB. But when a slope is present, that response is going to be "best case scenario".
We went yesterday for pure-tone tests called "toneburst" and we got 500Hz, 2000Hz, and 4000Hz frequencies done. As expected, he has very good response at 500Hz--about 25dB--slightly worse than normal range. At 2000 and 4000 Hz it drops off dramatically to about 45dB and 60dB, respectively, so he will definitely benefit from early intervention services and amplification from hearing aids.
With such a dramatic curve at such an early age, we also definitely want him to be bilingual with ASL. This shouldn't be hard because I am already almost 2 years ahead of him learning ASL, and we will have help in the future, I am sure. I'm not sure who will help there, maybe Pennsylvania School for the Deaf. They are only like an hour away from us.