New approaches to exploring informational interference during speech-in-noise perception Seminar

Speech-in-noise research typically distinguishes between energetic masking (EM: interference between target and masker at the periphery) and informational masking (IM: interference higher in the auditory pathway). IM itself can be broken down into low-level and high-level IM. We use the term “informational interference” (inf-int) to refer to high-level IM involving linguistic and cognitive factors, and which is influenced by long-term knowledge (e.g. familiarity with the language spoken by competing talkers). Unlike EM, inf-int is poorly understood, in part because it is extremely difficult to manipulate inf-int without altering EM or lower-level IM.

In this talk, I will discuss the distinctions between EM, IM and inf-int, and highlight the need to identify and isolate the specific masker characteristics which contribute to inf-int. I will describe a new paradigm we are using to that end, which exploits the perceptual characteristics of a type of distorted speech called sinewave speech (SWS). SWS is not usually perceived as speech, but through training can be made at least partially intelligible. As a result, it provides a masker which can be kept identical across all participants (thus controlling for EM and lower-level IM), but the subjective intelligibility of which can be varied across participants. I will discuss preliminary results from a speech-in-noise study using the SWS technique, and briefly consider similar approaches to isolating other potential contributors to inf-int.