Measured total particle number concentrations were summed over the period of activity and divided by the duration of the activity, reporting a mean concentration (cm -3 ) with a standard deviation, i.e. the average concentration of particles sampled within the funnel volume during the activity. With coughs requiring < 1 s, no averaging across a time-dependent concentration is possible and only the integrated number concentrations per single cough are reported. Further, particle size distributions were recorded by the APS at 1 s intervals with 51 size bins equally spaced in the range 0.5 to 20 m in log(diameter) space. Average size distributions were calculated first by determining the mean size distribution for each participant and then calculating the mean and standard deviation across all participant size distributions for each activity. Mass concentrations were calculated assuming particle density was 1000 kg•m -3 . Our reported number concentrations and particle size distributions for speaking and breathing are consistent with previously published data. The lme package in R-software was used to fit linear random effect models with log-base-e transformed particle concentration or mass as the dependent variable. The independent variables were vocalisation (speaking or singing) and acoustic volume (50-60, 70-80 and 90-100 dB); the random effect was participant identification number. In the Figures, the lower and upper hinges (ends of boxes) correspond to the first and third quartile (the 25th and 75th percentiles). The upper whisker extends from the upper hinge to the largest value but no further than 1.5×IQR (where IQR is the inter-quartile range, the distance between the 1 st and 3 rd quartiles). The lower whisker extends from the lower hinge to the smallest value at most 1.5×IQR. Data beyond the ends of the whiskers are "outlying points" and indicated in red. All components of the box plots were calculated based on the logarithmically-transformed data, owing to lognormal nature of the data, but the plotted and tabular values reported are converted back to linear space for clarity.