subvocally


sub·vo·cal

S0858150 (sŭb-vō′kəl)adj. Characterized by movement of the lips or other speech organs without making audible sounds: subvocal speech.
sub·vo′cal·ly adv.

subvocally

(sʌbˈvəʊkəlɪ) adv (Linguistics) in a subvocal manner, with subvocalization