Before revision:  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). These results can help improve the existing public health guidelines for COVID mitigation by introducing a lateral shift between people during short conversations. Moreover, simulations like these can provide useful inputs to the existing epidemiological models for improving their reliability and accuracy .
After revision:  We show that the interaction between the two speech jets, than two faces at the same level! For small axial separation, speech jets show large oscillations and reach the other person intermittently. We suggest a range of lateral separations between two people to minimize transmission risk. A realistic estimate of the infection probability is provided by including exposure through eyes and mouth, in addition to the more common method of using inhaled virions alone. We expect that our results will provide useful inputs to the existing epidemiological models for improving their reliability and accuracy .