Preliminary study on phonetic characteristics of patients with pulmonary nodules.

Objective: Pulmonary nodules (PNs) are one of the imaging manifestations of early lung cancer screening, which should receive more attention. Traditional Chinese medicine believes that voice changes occur in patients with pulmonary diseases. The purpose of this study is to explore the differences in phonetic characteristics between patients with PNs and able-bodied persons.

Methods: This study explores the phonetic characteristics of patients with PNs in order to provide a simpler and cheaper method for PN screening. It is a case-control study to explore the differences in phonetic characteristics between individuals with and without PNs. This study performed non-parametric statistics on acoustic parameters of vocalizations, collected from January 2017 to March 2018 in Shanghai, China, from these two groups; it explores the differences in third and fourth acoustic parameters between patients with PNs and a normal control group. At the same time, computed tomography (CT) scans, course of disease, combined disease and other risk factors of the patients were collected in the form of questionnaire. According to the grouping of risk factors, the phonetic characteristics of the patients with PNs were analyzed.

Results: This study was comprised of 200 patients with PNs, as confirmed by CT, and 86 healthy people that served as a control group. Among patients with PNs, 43% had ground glass opacity, 32% had nodules with a diameter ≥ 8 mm, 19% had a history of smoking and 31% had hyperlipidemia. Compared with the normal group, there were statistically significant differences in pitch, intensity and shimmer in patients with PNs. Among patients with PNs, patients with diameters ≥ 8 mm had a significantly higher third formant. There was a significant difference in intensity, fourth formant and harmonics-to-noise ratio (HNR) between smoking and non-smoking patients. Compared with non-hyperlipidemia patients, the pitch, jitter and shimmer of patients with PNs and hyperlipidemia were higher and the HNR was lower; these differences were statistically significant.

Conclusion: This measurable changes in vocalizations can be in patients with PNs. Patients with PNs had lower and weaker voices. The size of PNs had an effect on the phonetic formant. Smoking may contribute to damage to the voice and formant changes. Voice damage is more pronounced in individuals who have PNs accompanied by hyperlipidemia.