There is a big difference between Wi-Fi hearing other Wi-Fi and Wi-Fi hearing non-Wi-Fi signals. The protocol is 100X more sensitive to other Wi-Fi than non-Wi-Fi...
So another Wi-Fi device on the same channel is called CCC - Co-Channel Contention... that IS how the protocol is designed to work. Only ONE Wi-Fi device can transmit at a time.
Other non-Wi-Fi device may 'Interfere' with your Wi-Fi... but Wi-Fi devices 'Contend' for the airtime.