STUDY OF PHARYNGEAL TONSIL HYPERTROPHY DETECTION BY USING PHONETIC SOUND

摘要

Lymphoid tissue of the pharyngeal tonsil becomes hypertrophied as acquired immunity improves during childhood. Generally, pharyngeal tonsil hypertrophy reaches its peak between ages 4 to 6 years and then the tissue atrophies. However, some cases have been observed in which the hypertrophy standing continuously whether the atrophy term is past. In these cases, detection of pharyngeal tonsil hypertrophy at an early stage is important because hypertrophied tissue may lead to sleep and breathing disorders. The two main modalities for the detection of pharyngeal hypertrophy currently available, cone beam computed tomography (CBCT) and roentgenographic cephalogram, are both invasive. Therefore, we propose a method for non-invasively detecting pharyngeal tonsil hypertrophy using phonetic sound. We use a discrimination system for pharyngeal tonsil hypertrophy focusing on the anti-formant because an obstruction of the pharyngeal cavity occurs due to hypertrophy of the pharyngeal tonsil. Cepstrum analysis performs as feature extraction for measuring resonance and anti-resonance. In this study, the speech of participants with pharyngeal tonsil hypertrophy was compared to the speech of healthy subjects using the proposed method. There were differences between participants with pharyngeal tonsil hypertrophy and healthy participants in wavelengths obtained in the first anti-formant frequency. Based on this result, it was concluded that pharyngeal tonsil hypertrophy may be detected using only phonetic sound.