On LSD (at least up to moderate doses), you don't hallucinate anything that doesn't exist. You don't see anything that isn't there, or hear voices, everything is just an altered version of reality.
Hallucinations from sleep deprivation (and certain drugs) are different though, you do start to see things that aren't there, often in the corner of your vision, and you do start to genuinely hear voices that don't exist. It's a surreal experience when you're suffering from severe sleep deprivation and you can hear your family talking to you, despite knowing that in reality they're 1000 miles away.
On LSD (at least up to moderate doses), you don't hallucinate anything that doesn't exist. You don't see anything that isn't there, or hear voices, everything is just an altered version of reality.
Hallucinations from sleep deprivation (and certain drugs) are different though, you do start to see things that aren't there, often in the corner of your vision, and you do start to genuinely hear voices that don't exist. It's a surreal experience when you're suffering from severe sleep deprivation and you can hear your family talking to you, despite knowing that in reality they're 1000 miles away.