Rhonchi is a coarse rattling respiratory sound somewhat like snoring, usually caused by secretion in bronchial airways. Rhonchi is the plural form of the singular word rhonchus. Since the mid-1990s, it has no longer been considered appropriate terminology in auscultation of the thorax as there has been much confusion in the published literature which confuses this between crepitations and wheezes, so the exact nature of this term is unclear (see Fleischner Society for standardized terminology). Similarly rales are no longer used in much of Europe, North America and Australia with regard to description of auscultatory findings. More appropriate terms for auscultation of the thorax are respiratory sounds, and adventitious sounds (wheezes, crackles, pleural rubs).
These have variably been associated with low-pitched, continuous sounds that are similar to wheezes and / or crackles.
Other terminology for sounds that may be auscultated in the thorax include crackles, wheezes, pleural rubs, pulmonary murmurs, egophony, whispering pectoriloquy and vocal fremitus. Also, percussion is often used to assess diseases of the chest.