Physical characteristics of sound and hearing.
D000162:Acoustics; D000388:Air; D001307:Auditory Perception; D001309:Auditory Threshold; D004423:Ear / Q000502:physiology; D006309:Hearing; D006326:Heart Auscultation; D006801:Humans; D009622:Noise; D010897:Pitch Discrimination; D013016:Sound; D014732:Vibration