Sonifying Ecog Seizure Data with Overtone Mapping: a Strategy for Creating Auditory Gestalt from Correlated Multichannel Data

This paper introduces a mapping method, overtone mapping, that projects multichannel time-series data onto a harmonic-series structure. Because of the common-fate effect of the Gestalt principle, correlated signals are perceived as a unity, while uncorrelated signals are perceived as segregated. This method is first examined with sonification of simple, generic data sets. Then overtone mapping is applied to sonification of the ECoG data of an epileptic seizure episode. The relationship between the gestalt formation and the correlation in the data across channels is discussed in detail using a reduced 16 channel data set. Finally, sonification of a 56channel ECoG data set is provided to demonstrate the advantage of the overtone mapping.