# Investigation of Vocal Fatigue Using a Dose-Based Vocal Loading Task
## 6 Discussion and Conclusions
An improved method of calculating \(D_{d}\) that considers voice quality is therefore needed to make the voice use quantification more accurate. Another limitation was that calculation of the \(D_{d}\) from the NSA may be not very accurate because of the rather large uncertainty in the SPL (\(\pm\) 5 dB) estimates from the NSA data [40]. The accuracy of calculating \(D_{d}\) would thus be influenced. This issue limits the use of the dose-based voice use quantification method in long-term voice monitoring. The monitoring of neck surface acceleration is preferable to minimize the influence of extraneous noise and potentially reduce discomfort in occupational settings. A method for directly deriving the magnitude of the vocal fold vibration from the skin acceleration level is therefore needed. The last limitation isthat normal swallowing on a daily basis was not measured, and thus the fatigue-indicative symptom analysis lacked a baseline to refer to. This baseline could be established in future work. Conceptualization, Z.L., N.Y.-K.L.-J. and L.M. ([PERSON]); methodology, Z.L. and L.M. ([PERSON]); software, Z.L. ; validation, Z.L., N.Y.-K.L.-J. and L.M. ([PERSON]); formal analysis, Z.L. ; investigation, Z.L. ; resources, L.M. ([PERSON]), N.Y.-K.L.-J. and L.M. ([PERSON]); data curation, Z.L., L.F. and L.M. ([PERSON]); writing--original draft preparation, Z.L. ; writing--review and editing, Z.L., L.F., L.M. ([PERSON]), N.Y.-K.L.-J. and L.M. ([PERSON]); visualization, Z.L. ; supervision, N.Y.-K.L.-J. and L.M. ([PERSON]); project administration, L.M. ([PERSON]); funding acquisition, N.Y.-K.L.-J. and L.M. ([PERSON]). All authors have read and agreed to the published version of the manuscript. This research was funded by the National Institutes of Health (Grant R01 DC-005788) and the Canadian Institutes of Health Research (388583). The financial support of of the National Science and Engineering Research Council of Canada is gratefully acknowledged. The authors declare no conflict of interest. The following abbreviations are used in this manuscript:  
C.-VConsensus Auditory-Perceptual Evaluation of Voice  
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