Lemme Get Some Sleep! by Hexagonal-Bipryamid
Heavy Sleepers won’t wake up when there are noises in the same room as them.
Light Sleepers will wake up when there are noises even outside of their room. If it’s outside of the room, the noise has to be somewhat near (about 6 tiles) for the Sims to be woken up.Both Heavy Sleepers and Light Sleepers can sleep regardless of their Energy level.(Added 2019-02-07) Pets are immune to noises too.
Everything Sims 2 