Before revision:  We propose an alternative method of estimating viral ingestion that includes exposure through the eyes and mouth , to provide more realistic estimates of the risk of infection . This method is then used to determine infection probabilities when two speakers facing each other are engaged in a short conversation. We show that the interaction between the two oppositely-directed speech jetscan increase or decrease infection probabilities, which peak for a height difference between the speakers of about 10cm (30cm) when the axial separationbetween them is 2ft (6ft).
After revision:  We propose an alternative method of estimating viral ingestion that includes exposure through the eyes and mouth , to provide more realistic estimates of the risk of infection to the person who talks less. Interestingly, a small height difference is worse for infection spread, due to reduced interference between the two oppositely-directed speech jetscan increase or decrease infection probabilities, which peak for a height difference between the speakers of about 10cm (30cm) when the axial separationbetween them is 2ft (6ft).