Influence of acoustic rhinometry, rhinoresistometry and endoscopic sinus surgery on voice quality.

Twenty-one patients with documented chronic paranasal sinusitis, being in need of endoscopic endonasal sinus surgery were subjected to voice analysis. Tape recordings of sustained vowels were performed both pre- and postoperatively. All voice samples were examined with a system of sound spectrographic analysis. Patients with nasal obstruction, detected by active anterior rhinomanometry were excluded from further studies. Analysis of pre- and postoperative spectograms was focused on changes in center frequency as well as on a bandwidth of the initial four formants. The variations in specific differences of the formant frequencies and amplitudes were also estimated. The different subgroups of patients revealed significant alterations in the parameters studied. The vowels [a:] and [i:] showed inverse changes in measured values. Evaluation of the vowel [u:], on the other hand, was restricted due to artifactual scattering of individual values. In general, the bandwidths diminished postoperatively and energy peaks of formants increased proportinally. In 6 out of 21 patients, one third of the cases examined, after surgery the patients detected perceptual changes in speech. Based on our data obtained it is recommended to inform all patients as well as voice professionals about the possible speech alterations of the speech after endonasal sinus surgery.