My voices have occurred at all times of the day and night. But I think that it is certainly possible to hear them only at bedtime. I no longer hear voices unless really under stress, but I still hear other noises that are not really there. Like I hear my cell phone ringing about the time I wake up in the morning, and it is not really ringing. I have also had a single word shouted at me after I get to sleep, and that wakes me up in a panic. Most disconcerting.
But Dave is right -- medication prescribed by your doctor is the thing most likely to get rid of the voices, no matter what time of day they occur.
Best wishes,
Carolyn