I've never taken Ambien, but I have heard the voices the author describes. I think they're fairly normal while falling asleep–they're called hypnagogic auditory

I've never taken Ambien, but I have heard the voices the author describes. I think they're fairly normal while falling asleep–they're called hypnagogic auditory hallucinations: https://patient.info/doctor/hypnagogic-hallucinations https://patient.info/doctor/hypnagogic-hallucinations > Auditory hallucinations are common but other senses are seldom involved. Auditory hallucinations can range from a few sounds to an elaborate melody. Threats or criticism are also reported. In my case, sometimes it's music (usually quite beautiful, and forgotten the next morning) and sometimes like a news broadcaster conveying quite a lot of information (again, quite forgotten the next day).