THE ACCURACY OF ACOUSTIC RHINOMETRY USING A PULSE-TRAIN SIGNAL

The signal used in the original acoustic rhinometers was an impulse of short duration and wide energy spectrum. A rhinometer utilizing a new signal of a similarly broad energy but different time course has been developed. We investigated the accuracy of area reconstructions compu ted using this signal by comparing them with the original areas of sim ple models. This study demonstrates that, at present, acoustic rhinome try using a pulse train signal is subject to significant systematic er rors. Some of these are intrinsic to the rhinometer. Others are caused by the geometry of the models. Area reconstructions beyond narrow con strictions are particularly inaccurate. The findings are significant b ecause the nasal valve can act as such a constriction. The errors can cause the parameters used in the clinical application of acoustic rhin ometry to deviate substantially from the true values.