Experimental study of pharyngeal tonsil: A resonance model

The pharyngeal tonsil of lymphoid tissue becomes hypertrophied as acquired immunity improves during childhood. Generally, pharyngeal tonsil hypertrophy reaches its peak between the ages of 4 to 6, and then the tissue atrophies. However, some cases hypertrophy continues even though the atrophy term has passed have been observed. In these cases, the hypertrophied tissue may lead to sleep and breathing disorders. The many currently available modalities for the detection of pharyngeal hypertrophy are invasive. Therefore, we developed a method for non-invasively detecting pharyngeal tonsil hypertrophy using phonetic sound. In this study, as a fundamental experiment, we verify that the acoustic change due to obstruction of PVC pipes can be detected from the transfer function. There were differences in the frequency response characteristics and impulse responses between PVC pipes with different obstruction rates which indicated that acoustic change due to obstruction can be detected from the transfer function.