Listening Effort: Cardiovascular Investigation Through the Point Process

In the context of quantifying listening effort, traditional hearing tests do not provide any information about the stress experienced during listening tasks. Although there have been attempts to quantify memory allocation during acoustics tests, there is no agreement in the literature regarding the role of physiological indices in characterizing different listening effort levels. To this extent, the aim of our study is to ascertain if cardiovascular measurements continuously recorded during the task can help in quantifying listening effort. In the presented protocol, 21 normal young hearing subjects performed a validated speech-in-noise test at two fixed effort levels, while electrocardiogram (ECG) and blood volume pulse (BVP) were continuously recorded. From these time series, the RR series, the amplitude difference between each systole and diastole and the pulse arrival time were extracted. In addition, the ECG-derived RR series were modelled trough a point process framework, yielding instantaneous cardiovascular and autonomic indexes to be considered in our statistical analysis. Overall, the average modelled RR intervals and the pulse arrival time were found effective in distinguishing the two different effort levels (p=0.031 and p=0.016). In addition, the amplitude difference between each systole and diastole was able to significantly separate high effort from both low effort and the initial resting period (p < e-3).