Crackles, crepitations, or rales (s {respell|RAHLS|`} or s {respell|RALS|`}) are the clicking, rattling, or crackling noises that may be made by one or both lungs of a human with a respiratory disease during inhalation. They are often heard only with a stethoscope (`on auscultation`). Bilateral crackles refers to the presence of crackles in bo... Found on http://en.wikipedia.org/wiki/Crackles