Nasal obstruction is evaluated by several methods, such as measurement of nasal resistance with a nasomanometer and of nasal capacity by acoustic rhinometry, while in everyday life nasal obstruction is sometimes impressed (evaluated) by an acoustic clue, i.e. hearing the voice.
In this study the possibility that acoustic impression allows evaluation of nasal obstruction was examined in normal volunteers and patients who underwent sinus surgery. The acoustic impression of nasal obstruction, the nasal flow resistance and the nasal cavity volume were compared with self-evaluation values of obstruction. The coincidence rate of evaluation by acoustic impression is equal to that of the nasal flow resistance. Acoustic analysis of the humming sound suggests a possibility that the nasal obstruction indicator is in the regions below 800Hz and above 3000Hz.