Interaural differences

[Concepts in Sensorimotor Research]

Interaural differences refer to the differences between the sound signals that reach each ear. These differences are caused by the time delay and the amplitude difference of the sound waves that reach each ear.

• ITD (interaural time difference): time delay between the arrival of sound at each ear. ITD is greatest for sounds coming from the side of the head and is zero for sounds coming from directly in front or behind the listener.
• ILD (interaural level difference): amplitude difference between the sound waves arriving at each ear. ILD is greatest for sounds coming from directly to one side of the listener and is zero for sounds coming from directly in front or behind the listener.

The brain processes these interaural differences to determine the location of the sound source and create a spatial auditory image, which helps us to perceive the world around us in three dimensions.

Some studies have reported differences in how autistics process interaural differences, including reduced ability to integrate auditory and visual information, as well as altered auditory and multisensory temporal processing. 

The caveat being, more research is needed in this area for better understanding. Nothing is set in stone when it comes to autism. 

References
Foss-Feig, J. H., Kwakye, L. D., Cascio, C. J., Burnette, C. P., Kadivar, H., Stone, W. L., & Wallace, M. T. (2010). An extended multisensory temporal binding window in autism spectrum disorders. Experimental Brain Research, 203(2), 381-389.
Jeste, S. S., & Nelson, C. A. (2009). Event-related potentials in the understanding of autism spectrum disorders: An analytical review. Journal of Autism and Developmental Disorders, 39(3), 495-510.
Kwakye, L. D., Foss-Feig, J. H., Cascio, C. J., Stone, W. L., & Wallace, M. T. (2011). Altered auditory and multisensory temporal processing in autism spectrum disorders. Frontiers in Integrative Neuroscience, 4, 129.