quality or fact or degree of being audible or perceptible by the ear

impossible or difficult to perceive by the mind or senses

free of noise or uproar; or making little if any sound

quality or fact or degree of being audible or perceptible by the ear

uttered without voice

having frequencies below those of audible sound

having a frequency below or above the range of human audibility

not made to sound

having frequencies above those of audible sound