Comparison of (A) emission rate/concentration and (B) corresponding geometric mean diameters of particles emitted during various modes of breathing versus speech at different loudness levels. “Nose” denotes normal nasal breathing; “Mouth” denotes normal mouth breathing; “Deep-Fast” denotes deep, slow nasal inhalation followed by fast mouth exhalation; “Fast-Deep” denotes fast nasal inhalation followed by deep (i.e., slow and prolonged) mouth exhalation. “Quiet”, “Intermediate”, and “Loud” denote loudness levels while reading aloud a passage of text (“Rainbow” passage) at respective amplitudes. Red lines indicate medians, while bottom and top of blue boxes indicate the 25th and 75th percentiles respectively; sample size is n = 10. Outliers (defined as values that exceed 2.7 standard deviations) are indicated with red plus signs. Note that the 2 outliers for speech in (A) are a different individual (F4) than the two outliers observed for nose and fast-deep breathing (M24 and M5 respectively). Scheffe groups are indicated with letters; groups with no common letter are considered significantly different with p < 0.05, cf. Supplementary Table S1. Note that (A) has different scales above and below the break.