murmur

Murmur is a term used to describe a soft, indistinct sound produced by a disturbance in a medium, such as air or liquid. It can refer to a variety of everyday noises, including ambient background sounds, a whispered complaint, or a gentle natural sound like wind or a flowing stream.

In medicine, a heart murmur is an abnormal sound heard during auscultation with a stethoscope, resulting from turbulent blood flow within the heart or great vessels. Murmurs are described by their timing (systolic or diastolic), quality, and loudness, and are often graded on a scale from 1 to 6. Many murmurs in children or healthy adults are benign, or innocent, but others reflect underlying heart conditions such as valvular stenosis or regurgitation, congenital defects, or heart failure. Evaluation typically includes physical examination and, when indicated, echocardiography to visualize heart valves and flow patterns.

Outside medicine, murmurs can describe quiet natural sounds, such as a brook babbling over stones or wind rustling through trees. The term also appears in literature and everyday language as a verb meaning to murmur or to speak in a low, indistinct voice, or as a noun for a low, continuous whisper or protest.

Etymology traces the word to Middle English and Latin roots related to murmuring sounds, reflecting its long association with soft, unresolved noise.