My research aims to develop a better understanding of the neural operations necessary to detect and utilize sound patterns in our environment, how situational demands affect those neural operations, and how aging and hearing impairment changes sound-pattern processing. Hopefully, this work will help in the future to make hearing easier for people with hearing difficulties, for example, by identifying biological markers for early diagnosis and treatment of impaired hearing.
In my research, I focus on perception, because perception brings humans into contact with the environment. We would not be able to live without sensory systems enabling us to perceive. Perception allows us to interact and behave in the world. I investigate how the brain enables humans to perceive sounds, or more specifically how patterns in sound environments shape perception. Many auditory researchers focus on the individual elements of sounds, such as sound amplitude or frequency. In contrast, I focus on how perception is shaped by the patterns or structure across these individual elements. In more scientific terms, a sound pattern is a statistically ordered structure in sounds. Important sound patterns are temporal regularities or sound repetitions, correlations between sound features, and properties of sound feature distributions. Detection and utilization of these and other patterns is crucial for perceiving any behaviorally relevant sounds, including speech and music. If the auditory system fails to detect patterns, no meaning can be extract from a sound environment and a listener is left with a noisy-sounding percept.
In addition, I aim to understand why some individuals experience difficulties listening to sounds and the extent to which sound-pattern processing is impaired in these people. Hearing impairment is listed as being among the four major chronic diseases. Hearing impairment affects over 1.3 billion people worldwide, which is more than 10% of all people on this planet. A large proportion of those people are older individuals, and this number is likely increasing given our aging Western societies. The problem is even bigger. Hearing impairment is usually diagnosed very late, up to 20 years after hearing difficulty onset. Impaired hearing to sounds at moderate sound levels, such as speech, is not even detected with standard hearing assessment. We call this hidden hearing loss, which increases the overall number of people with degraded hearing even further. Hidden hearing loss is a likely reason why many older individuals experience hearing difficulties even in non-challenging listening situations like listening to one’s spouse while the TV is on. As a consequence, by the time we treat hearing impairment with, for example, a hearing aid, the brain has undergone quite drastic structural and functional changes, for which we do not know how they affect sound pattern processing.