Squeaky wheels: Friction-generated sound supports auditory differentiation and scaling of rotating ellipse shapes.

Acoustical analysis indicates that sounds generated as the rims of ellipses rotate against a fixed contactor vary regularly with ellipse shapes (defined by minor-to-major axis length ratios), potentially supporting human ability to differentiate and scale the shapes. In four experiments, we documented human ability to do so. Experiment 1 demonstrated reliable and ordinally correct shape judgments.

Change deafness, dual-task performance, and domain-specific expertise.

In a change deafness manipulation using radio broadcasts of sporting events, we show that change deafness to a switch in talker increases when listeners are asked to monitor both lexical and indexical information for change. We held semantic content constant and demonstrated a change deafness rate of 85% when participants listened to the home team broadcast of a hockey game that switched midway to the away team broadcast with a different announcer. In Study 2, participants were asked to monitor either the indexical characteristics ( listen for a change in announcer) or both the indexical and semantic components ( listen for a change in announcer or a goal scored).