A new laboratory to study brain dynamics of soundscape in virtual environment

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Our auditory environment is comprised of many sound sources (such as the wind rustling the leaves of the trees nearby, a dog barking, and a car driving by). Acoustic energy from every sound source in our surroundings sum together to form a single soundwave that enters the ear. How does the brain manage to make sense of that single composite wave, such that we can deconstruct it and perceive and identify these three separate auditory objects? One prominent theory borrowed from Gestalt psychology is that of auditory scene analysis: sounds that are similar in pitch and location, and that “move” together, are likely to originate from the same physical object. While this theory works reasonably well in predicting the outcome of very simple sounds in the laboratory, it has not been tested in more complex and real-world sound settings. Prior knowledge has been shown to facilitate the perception and recognition of a familiar voice or melody in adverse noisy environments. How does prior knowledge impact the grouping based on acoustic cues? How does prior knowledge, attention, and automatic processes interact with one another during auditory scene analysis? Answering these questions will advance theories of auditory perception and training programs for improving listening skills in adverse listening conditions, especially for populations with hearing difficulties. We want to test the limits of current theories of auditory perception by collecting data using more ecologically valid stimuli. To accomplish this, we need a workstation that can operate several audio channels, allowing users to mix different environmental sounds and to digitally create a mixture of different soundwaves (i.e., soundscapes) of a particular environment (e.g., ambient city soundscapes in Toronto). This workstation will allow brain health and aging experts at Baycrest Centre to use immersive virtual technology in a well-controlled lab setting to piece together how the brain figures out soundscapes. Such a novel workstation capable of creating controlled yet more ecologically valid auditory environments will (1) further enhance the momentum of auditory cognitive research at Baycrest Centre; (2) support ongoing and future collaborations in the area of auditory scene analysis, and (3) ultimately advance our understanding of links between hearing and how we understand and interact with our environment. This new and emerging technology will provide exceptional and unique training opportunities for students. Trainees working in the lab will gain a set of marketable skills (such as coding, critical thinking, writing, public speaking) applicable for academic careers in fields such as cognitive neuroscience and experimental psychology, or careers in the private sector such as in sound engineering and virtual/augmented reality.