I cannot say how many time I've had to debunk the myth of multitasking. Here's a good breakdown for all crowds.
https://goodmenproject.com/guy-talk/smart-people-dont-multitask-fiff/
@arteteco
So the short answer is multitasking doesn't exist: our brains are not paralell processors so we are not able to hold two or more tasks/inputs simulateously. Rather, we are serial or sequential processors, switching (our attention) rapidly back and forth between or among tasks. The research has established that as the frequency of switching, as well as an increase in number of tasks, the quality and efficacy of the outcom are of our efforts deteriorates. That is to say, we perform worse the more we go back and forth between or among multiple things. Memory formation and retention also suffers.