During this project we developed multiple behavioural paradigms in an animal model, which provide us with a foundation to define the underlying neural mechanisms. Throughout the project, in parallel to our behavioural work in animals, we deployed near-identical tasks in humans. Each task pinpoints a particular aspect of auditory scene analysis. For example, in humans we explored how rapidly listeners can adapt to background sounds and whether the brain does this by building a model of the ‘noise’ as a distinct source. Consistent with this, we found that if the noise changed in type (for example from a lawnmower to running water) or in location, listeners required a similar period of time to adapt to the new noise background. We found that these abilities were preserved in listeners who were older, and in those with hearing loss.
In our animal model we used an identical task where animals identified brief speech sounds (artificial vowels), as well as tasks that required animals identify statistical regularities in sounds, or discriminated streams of speech in background noise. Through these tasks we were able to show that many of the listening abilities that humans deploy to make sense of sound in noisy situations are found in non-human animals. These include extracting statistical regularities, linking sounds from a common source according to their fundamental frequency, and preserving speech sound discrimination in background noise. We then recorded neural activity from a network of brain regions during behaviour in order to understand how the brain is able to ‘tune out’ background noises, and allow us to focus on sounds of interest.
We have published a number of scientific outputs (11 to date) including methods developments (see following section), behavioural results and some key findings from auditory cortical recordings. Multiple publications further manuscripts are in preparation for human work, and from neural data collected during task performance that explore how the auditory cortex represents multiple simultaneous sounds, and how auditory cortex is shaped by activity in other brain areas to allow us to select which sound in a mixture to listen to.
Our results have been disseminated through multiple scientific conference presentations, including keynote presentations and seminars by the PI, competitively awarded talks and oral papers, as well as poster presentations at national and international meetings around the world by the trainees funded by SOUNDSCENE. Trainees funded in whole or in part by SOUNDSCENE have written four PhD thesis, all of which are openly available on UCL Discovery.
Results from SOUNDSCENE are currently being used as a foundation for multiple grant applications and fellowship applications by the PI and trainees funded by the award.
