“Dry rales are an additional sound heard during auscultation of the lungs in addition to the normal breath sounds.
Depending on the nature of the sound, it can be divided into Sonorous, which is low-pitched and loud, and Sibilant, which is high-pitched. The croup is a dry rumbling sound, also known as a “whistling sound”, usually of a high pitch, and is most often heard in bronchial or fine bronchitis and bronchial asthma.”