The most obvious way in which human beings perceive sound is through the organs of the ears. The ear drum, which is a specialised membrane which vibrates with the input of sound waves, or pressure. However, many members of the animal kingdom perceive sound through other sensory organs, and human beings are no different. Even those who are born profoundly deaf can interpret sound, but in this instance as a vibration. For example, if we feel the vibration through our feet we are able to dance to the rhythm of music regardless of whether we can hear it or not.