People often perform more than one task at a time, without even realizing it. Many situations in everyday life involve understanding speech and, at the same time, solving a task visually. For example, in a professional context, one may need to listen to a colleague speaking while identifying information on a screen. Similarly at home, one may want to listen to someone talking while doing other tasks at the same time. Despite being common situations, performing more than one task at a time is often challenging, and one may need to prioritize one task over the other(s) to maintain a certain level of performance. This is because performing one or more tasks requires using cognitive capacity.
The clinical study* presented in this whitepaper evaluated the potential benefits of noise attenuation in audio devices, while people performed a dual task consisting of understanding speech while reacting as fast as possible to a visual task. The goal was to evaluate how noise attenuation affects speech-in-noise recognition, listening effort, reaction time, accuracy, and overall cognitive resource allocation in a dual task paradigm.
The research was conducted by EPOS at the Centre for Applied Audiology Research (CAAR)1, Oticon, Denmark, with a focus on pupillometry tracking, speech recognition performance and subjective listening effort ratings for each noise condition. The users performed the listening and visual task when the background noise was Attenuated and when the background noise was not Attenuated, with the visual task only used as the baseline.
The results of the study indicate that noise attenuation provides several benefits for participants with normal hearing when performing a dual task is required. When noise was attenuated during a dual task, speech-in-noise recognition improved up to 48.2 percentage points and reaction time on the visual task improved up to 23.9% (i.e., the key was pressed 300 ms faster) without compromising accuracy, leading to an increase in efficiency up to 40.6%. Additionally, applying noise attenuation led to a significant decrease in perceived listening effort, on average, up to 67.5 percentage points relative to No Attenuation, as reflected by the subjective listening effort ratings. When the noise was attenuated, pupil dilation was also significantly reduced while listening to the sentence indicating less listening effort. Freeing up cognitive resources allowed the participants to perform the visual reaction time task quickly and accurately.
This study is just one example of decades of psychoacoustic research conducted by the Demant Group, of which EPOS is proud to be a part. The learnings collected in this study and others, are applied in ongoing development of EPOS BrainAdapt™ solutions, which are designed to support the brain’s natural way of processing sound.
* “The effect of noise attenuation on listening effort, efficiency and reaction time, while performing a dual task”
Federica Bianchi1, Torben Christiansen2
1 Oticon A/S, Smørum, Denmark, 2 EPOS, Ballerup, Denmark