For whatever it's worth, despite sightings, tracks, etc., I've never heard a howl "as shown on tv." I've heard a few other things, but not that.
So far as recording, my used-to-be research partner chewed my "tailfeathers" one day for not running a recorder and missing something very, very cool and apparently very rare. It's been 7 years now and I'm still looking for a repeat. Now I essentially NEVER go into the woods now without a recorder running. Couple ounces, a few $$ for batteries, and awareness of a small external mic on my pack that I need to be mindful not to tear off with a branch ... that's all it costs. While audio won't prove anything, not running audio means discarding the outside chance of having something pretty cool to share.
MIB