Occasionally i get a tonal difference between my 2 ears.where in one ear everything is off a few semi tones. any idea what could cause this?

Good question: This is something that you may want to have confirmed by an audiologist. Frequently, a person may have damage to certain hair cells that are responsible for hearing. These are an array of cells that are specialized in the sense that they subserve a specific set of frequencies. Thus, if certain cells are damaged through age or excessive noise, you may get specific "tone deafness"