how do cats purr? – Medical Physics Zone

Question: how do cats purr?
- Keywords:
  animal,
  cat,
  sound
Asked by slj1997 to Charlotte, Dhvanil, Frank, Jim, Leila on 14 Mar 2013.
- Dhvanil Karia answered on 14 Mar 2013:
  
  Cats produce the purring noise by using the vocal folds and/or the muscles of the larynx to alternately dilate and constrict the glottis rapidly, causing air vibrations during inhalation and exhalation.Combined with the steady inhalation and exhalation of air as the cat breathes, a purring noise is produced with strong harmonics
  
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Question: how do cats purr?