Introduction
Speech and voice are essential parts of communication in daily life. Nasal resonance plays an important role in speech quality. The subjective perception of nasal sounds is defined as nasality, and it may change with the patency of the nasal cavity. A structural alteration of the nasal cavity, related to sinonasal disease or surgery, may cause voice quality changes.1 According to the different proportion of vocal amplification in the sinonasal cavities, abnormal nasality can classify into hypernasality, hyponasality, and mixed resonance.2 Hyponasal voice may be related to nasal structural obstructive pathologies, such as rhinosinusitis, nasal polyposis, or nasal septal deviation.3 On the other hand, the voice of patients with cleft palate or velopharyngeal incompetence usually presents as hypernasality. Traditionally, objective examination of voice quality was subjectively evaluated by speech pathologists using auditory perceptual methods. A nasometer is a portable, noninvasive, and computer-based machine that provides an objective evaluation of nasality called nasalance. The nasometer is widely used to evaluate changes in nasality.4-6
Abnormal nasality is a common complaint; however, not much attention has been paid to nasality in patients with sinonasal disease before. Chronic rhinosinusitis (CRS) is an inflammatory condition of the sinonasal mucosa, which includes the lining of nasal passage and paranasal sinus. The swollen mucosa and congested nasal passage will decrease the resonance of the nasal cavity and cause abnormal nasality.7 Surgical interventions may change the sinonasal structure and airway passage. Volumetric changes in the nasal cavity will cause alterations in voice quality and resonance8. Jiang et al. reported that an increase in nasalance after functional endoscopic sinus surgery (FESS) correlated with an increase in midnasal and postnasal volumes.9
Previous studies have presented nasalance change in CRS patients with bilateral high disease burden after FESS.1,10,9,11However, nasality change in patients with only one side nasal airway involvement has not been well investigated. Hence, the impact of unilateral sinus surgery on nasality is not well known. Herein, we aimed to investigate the prevalence of abnormal nasality in patients with unilateral CRS. The subjective and objective nasality outcomes after unilateral sinus surgery were measured and analyzed.