adjective / noun
soporific
sah-puh-RIF-ik/ˌsɑːpəˈrɪfɪk/
Causing sleepiness, or something that does so.
The soporific lecture leaves the woman struggling to stay awake.

Etymology
Latin sopor means “deep sleep,” so something soporific brings on sleepiness. When applied to dull material, the word presents boredom as having a sleep-producing effect.
In context
Or you could just leave the television or the or the radio on just on a um a talking channel only so that it's just soporific calming human noises.
More examples
- The warm room has a soporific effect on everyone.
- For him, a long train ride is a reliable soporific.
- She avoids medications with soporific effects before driving.
Forms
soporific · soporifics
drowsiness noun — a feeling of being ready to sleep
Similar words
- sedative
- Emphasizes calming effects, which may also include sleepiness.
- sleep-inducing
- Directly describes bringing on sleep, without suggesting boredom.