Perceived odor intensity as a function of air flow through the nose.

The relationship between perceived odor intensity and flow rate during inhalation was studied. Thirty subjects, mainly students of psychology, participated. The odor from a solution of pyridine and water (0.5 ml/liter of H2O) was inhaled at five different flow rates, ranging from 75 to 1000 ml/sec. Three different conditions of sniffing were used, i.e., constant-duration sniffing (2 sec), constant-volume sniffing (1000 ml), and three successive short sniffs. The perceived odor intensity, expressed with a magnitude-estimation method, was found to increase with flow rate under all sniffing conditions.