Abstract: A system for diagnosing sinusitis in a human subject including: a miniature transducer for emitting a sound signal; a miniature microphone for detecting sound signals; a transducer holder configured to contain the miniature transducer and a microphone holder configured to contain the miniature microphone, each configured to be inserted into a nostril of a human subject; signal processing apparatus for controlling sound signals emitted by the miniature transducer and for processing sound signals detected by the miniature microphone; and data analysis apparatus for analyzing the processed detected sound signals, which includes a data storage device for storing processed sound signals, baseline signals representing measurements taken on healthy and variously-infected subjects, and programs for data analysis for reaching a diagnosis.