We kept Loki (our Bengal) in the bathroom with the litterbox for several months until we could "trust" him to behave in the apartment. He howled & meowed there too. Then when we let him out to roam, he got spoiled to it. Then Daniel started getting allergic to him, so we banned him from sleeping in our bedroom. That poor cat howled outside our bedroom, because he really liked sleeping on our feet at night and snuggling with us and waking us up for attention and playing around on our bed at night.

One thing I noticed was that if we started meowing back at him it seemed to make the howling episodes shorten, occasionally. He'd just kind of look at us like "Say what?! Reoooooow." And we'd go back and forth like that. I could probably call you and talk to you in Bengalspeak pretty well, that's how good I got. Other times we just ignored him & put on some sort of white noise, like the ceiling fan or the tv to drown him out, and maybe a towel at the base of the door to drown out some more of the noise. Eventually he did get the hint that he wasn't allowed in our bedroom & that he needed to find ways to entertain himself at night (find bugs, sleep, stalk the magazines, etc). I think time will be the deciding factor for this lil guy.