adjective. impossible to hear; imperceptible by the ear

"Abetted by digital technology, in deep sync with the info-tech surge in the Indian economy, her Indian literary supernova today is a force for liberating language communities, women and what used to be "untouchable" or "unhearable" voices."

breathed  infrasonic  silent  supersonic  ultrasonic  

unbearable  

echoless  hush as death  hushed  inaudible  inaudible