While waiting to find a neurologist who will answer my questions about the brain’s ability to handle two or more aural stimuli at the same time, I will report some personal experiences on the subject.
I would be glad to hear from any of you who have had similar experiences dealing with two or more stimuli of any kind.
In practicing a Bach prelude, in which each hand plays a separate and independent line, I can hear the right hand without effort, but even with intense focus on the left hand part, there are times when I cannot hear it, and therefore make many mistakes.
In playing the slow movement of a Mozart sonata, I cannot hear the repeated rhythmic sixteenth notes that accompany the melody of the right hand – I only hear the right-hand melody, and must look at the left to insure I am playing what is written.
In reading aloud a book about dogs, I read accurately – even dramatically - while thinking clearly about something entirely different – plans for dinner, appointments for the next day, a movie I have recently seen.