ungrating
/ˈʌŋɡreɪtɪŋ/Definitions
1. adjective
not grating or harsh; smooth, quiet, and free from harsh or unpleasant noises
“The ungrating sound of the ocean waves helped her relax.”
2. noun
a person who does not grumble or complain
“She’s always been an ungrating person, never complaining about anything.”