The respiratory sound features of COVID-19 patients fill gaps between clinical data and screening methods

Ying hui Huang; Si jun Meng; Yi Zhang; Shui sheng Wu; Yu Zhang; Ya wei Zhang; Yi xiang Ye; Qi feng Wei; Nian gui Zhao; Jian ping Jiang; Xiao ying Ji; Chun xia Zhou; Chao Zheng; Wen Zhang; Li zhong Xie; Yong chao Hu; Jian quan He; Jian Chen; Wang yue Wang; Chang hua Zhang; Liming Cao; Wen Xu; Yunhong Lei; Zheng hua Jian; Wei ping Hu; Wen juan Qin; Wan yu Wang; Yu long He; Hang Xiao; Xiao fang Zheng; Yi Qun Hu; Wen Sheng Pan; Jian feng Cai

Among them, asymmetric voice tremor and rales were the abnormal breath sounds that were easy to detect. For each patient, only one or more abnormal breath sounds were described in each doctor's auscultation results, in which the patient was recorded as abnormal breath sounds and the diagnosis was positive. Based on the above method, 1 of the 8 patients was diagnosed with abnormal breath sounds by 6 physicians at the same time. 2 patients were diagnosed by 5 physicians at the same time, 4 patients were diagnosed by 4 physicians at the same time, and only 1 patient was found to have abnormal breath sounds by 3 physicians ( Table 2 ). The diagnosis results of respiratory sounds in the asymptomatic patients included cackles, asymmetric vocal resonance, and abnormal vesicular breath sounds with murmurs. Asymmetric vocal resonance with the highest diagnostic consistency amongst 6 physicians. We use signal analysis to quantitatively describe this abnormal breath sound. After extracting the audio of bilateral vocal resonance in the anterior chest (Figure 1.A-B) , we drew the waveform and spectrum ( Figure 1 .C). It can be seen that the frequency distribution of breath sounds on both sides is similar, but the left breath sound intensity significantly increases, which is consistent with the CT results (See Figure 1 . for more details). Except for asymmetric vocal resonance, cackles were another common abnormal breath sound according to the auscultation results ( Table 2) . We quantified the signature of one signal of cackles, which was diagnosed by three physicians as a group, to validate the physicians' auscultation results. The feature of waveform and time-frequency graph (Figure 2 .B-C) are consistent with previous description concerning cackles features: duration <100ms, and the main frequency range is about 200-600Hz.