Long-term average spectrum loudness variation in speakers with asthma, paradoxical vocal fold motion and without breathing problems

Introduction: Vocal loudness variation can influence the reability of acoustics analysis. Therefore an intensity acoustic measure such as the Long Term Average Spectrum (LTAS) should be submitted to standard calibration and analysis procedures for realistic results. Purpose: The purpose of this study is to compare the LTAS intensity measures with and without implementation of intensity averaging procedures (calibration) in three different groups: asthma, paradoxical vocal fold motion disorder and asthma, and control group. Methods: Eighteen women of similar age were divided in 3 groups according to their diagnosis. Six women had asthma, six women had asthma and paradoxical vocal fold motion disorder and 6 women did not have breathing or voice problems. They were recorded according to a systematized procedure in studio conditions. Fifty-six speech samples were obtained. Those speech samples were submitted to averaged intensity procedures and compared to 56 speech samples not submitted to averaged intensity procedures according to a cluster analysis. Statistical analysis was made according to a six cluster division. Results: Cluster’s distribution was almost the same when comparing samples with and without intensity averaging procedures. However two speech samples were considered different according to the intensity procedure. It shows that the loudness variation has an impact in the LTAS acoustic analysis. The comparison among the three different diagnoses was also analyzed according to cluster analysis considering the calibrated samples. The LTAS analysis among the three groups indicated a tendency to grouping the patients with asthma in specific clusters and to conglomerate PVFM and control subjects in same groups. Conclusions: Once LTAS analysis represents the vocal quality it is suggested that asthma patients have specific vocal quality features that differentiates from PVFM and control individuals. This acoustic method can be a useful approach in the diagnosis of these diseases.