This has to do with right vs. left brain theories, in fact the right and left ears process sound differently, the left hemisphere of the brain dominates over the right in processing different sounds, this actually dominates in processing rapidly changing sounds such as in speech and words, and is important to take into consideration that the left side of the brain is the analytical part of the brain that’s why it is stimulated in processing the information more than the right ear. Same for the right ear, which dominates in processing prolonged tones such as in music and it, is also known as the creative side.
As for the phone calls, generally if you are a caring person you will put the phone to the right ear. Also, generally, when someone gets a call from someone they care about, they will put the phone to the right ear more frequently than the left.
