Modulation Detection Interference as Informational Masking

Abstract

The elevation in thresholds for detecting amplitude modulation (AM) of a probe tone due to modulation of a masking tone is referred to as modulation detection interference (MDI). Past work has suggested a relationship between MDI and auditory grouping with a possible, though not necessary, basis in the similarity of concurrent probe and masker modulation. An alternate but related approach is to view MDI in the context of informational masking. As nonenergetic masking at the peripheral level with similarity of probe and masker a component, MDI exhibits characteristics used to describe informational masking (e.g., Watson 2005). The intent of the present work was to evaluate MDI in the context of informational masking, using a more stringent definition which extends energetic masking to the modulation domain. To allow for consideration of auditory grouping and segregation effects, envelope slope and concurrency of modulation were manipulated in experiments I and II, respectively.