We hypothesized that most patients with severe pulmonary COVID-19 were exposed to cough aerosols. Among patients that were almost 100% certain which person infected them, only 14 out of 38 overall, and 9 out of 25 hospitalized patients requiring supplemental oxygen, were infected by someone who coughed, which did not support our hypothesis. Talking, especially with a loud voice, could be an alternative source generating SARS-CoV-2 aerosols. Further research is needed to determine how SARS-CoV-2 spreads. Avoiding to talk when you are not wearing your mask and not talking with a loud voice, 'voice etiquette', could be other public health interventions worthwhile exploring.