Lateralization of Pitch Processing

In the perception of language, studies have shown that the right ear and left hemisphere (RELH) pair processes linguistic syllables more readily than the left ear right hemisphere (LERH) during simultaneous presentation. This phenomenon is known as the Right Ear Advantage (REA). This is believed to occur due to the proximity of language processing areas in the left hemisphere to the left hemisphere reception of cortical auditory signals predominantly from the right ear. An analogous Left Ear Advantage (LEA) has also been reported for pitch processing, presumably with its center of processing in the right hemisphere. The current study replicates and extends a previous finding of LEA for pitch processing using an experimental protocol involving a dichotic, single ear, pitch processing task where judgements in pitch are made using an AXB discrimination task. Results demonstrate that across most tone bases and tone difference conditions, the effect of ear of presentation is not significant. The LEA was found to be limited in that it achieves a significant difference between the ear of presentation only within the small tone difference condition when collapsed across all trials and frequency ranges. Moreover, some findings in this condition were near chance responding, demonstrating the need for more nuanced manipulations in testing parameters for human hearing. The 1,000Hz condition demonstrates the largest interaction effect, displaying significance in the small tone difference condition, thus informing where the phenomenon of LEA may be most prevalent