How auditory scene understanding can fail in special populations

One way to gain insight into how the brain normally processes auditory scenes is to explore the perceptual problems in special populations. In our lab, we are studying two types of listeners who, although very different, both have trouble making sense of complex scenes: listeners with autism who are minimally verbal (MVA listeners), and blast-exposed military Veterans. Neither population shows evidence of specific deficits in how well information is encoded subcortically. However, both show deficits when it comes to analyzing sound mixtures with multiple sound sources. Neural responses from MVA listeners suggest that their brains do not automatically organize sound mixtures that typically developing listeners hear as distinct objects, which likely impairs their ability to analyze the content of one sound source in a mixture. In contrast, Veterans exposed to blast appear to have difficulties focusing selective attention on a sound source in order to select it from a mixture, consistent with behavioral defi...