obscuration

US /ˌɑːb.skjʊˈreɪ.ʃən/
UK /ˌɑːb.skjʊˈreɪ.ʃən/
1.

sự che khuất

the act of preventing something from being seen or heard, or something that prevents something else from being seen or heard:

:
Obscuration can be obtained by the use of blackout curtains.