subvocal
/sʌbˈvɒkəl/Definitions
1. adjective
relating to or produced by the vocal cords without audible voice; whispery
“The subvocal whispering in the quiet room sent chills down my spine.”
2. noun
the sound produced by the vocal cords without audible voice; whispering
“The subvocal murmurs of the crowd were barely audible.”