Effect of Septoplasty on Cepstral Analysis of Voice

Resonance change is a common clinical symptom in individuals with deviated nasal septum. Often this anatomical deficit is surgically treated by septoplasty. Therefore monitoring resonance changes using acoustical tools is vital. Hence, the study investigated cepstral measure differences in subjects with deviated nasal septum compared to normals. A case-control study design involving 20 subjects within 18-40 years divided into Group I of 10 subjects with deviated nasal septum (DNS) and Group II of 10 normal subjects participated. All the subjects sustained nasalized vowel /ã/ at 10 cm mouth-microphone distance for minimum of 5 seconds. For Group I, voice sample was recorded in 2 conditions, 2 days pre-septoplasty and 1 month post-septoplasty. Cepstral peak prominence (CPP) and smooth cepstral peak prominence (CPPS) values was extracted using the Hillenbrand algorithm. Mean values revealed increased CPP and CPPS measure post-septoplasty when compared to pre-septoplasty. ANOVA showed statistically significant difference only for CPPS at p = 0.00. The higher cepstral values of post-septoplasty is due to widened nasal passage that leads to increased nasal volume, decreased acoustic damping and increased nasal patency. These changes in supraglottic chambers will result in a better acoustic space for good resonance. However, the CPPS values were not similar to normal subjects because of scarring or incomplete recovery of the outer mucosal layer of the nasal tract. Thus, we can conclude that cepstral analysis is a sensitive tool to detect resonance changes in the nasal patency.