What is the defining characteristic of sonorous rhonchi?

Sonorous rhonchi are characterized by a low-pitched and continuous sound that is often described as resembling snoring. This distinguishes them from other respiratory sounds, such as wheezes, which are typically high-pitched and musical. The low-pitched nature of sonorous rhonchi indicates that they are produced by the obstruction of larger airways, commonly associated with conditions like bronchitis or other forms of airway obstruction. The continuous aspect of these sounds highlights their ongoing presence during respiratory cycles, particularly when the patient is exhaling.

In contrast to sonorous rhonchi, high-pitched wheezes would suggest a different type of airway obstruction, typically located in smaller airways, and intermittent sharp sounds could indicate conditions like pleuritic pain rather than an obstructive process. Hence, the defining characteristics of sonorous rhonchi are explicitly tied to their low pitch and continuous quality, making option C the correct choice.