Dimensions of self-reported listening effort and fatigue on a digits-in-noise task, and association with baseline pupil size and performance accuracy

Figures & data

Figure 1. Self-reported fatigue scores (VAS-F) for individual participants before and after performing the digits-in-noise-task. Solid lines represent increased VAS-F scores after task performance. Dashed lines represent decreased VAS-F scores after task performance.

Table 1. Pattern matrix: Factor loadings of the variables to each factor in the VAS-F.

	Component
	1	2	3
Item 1			–0.954
Item 2			–0.799
Item 3			–0.756
Item 4			–0.860
Items 5			–0.866
Item 6		0.891
Item 7		0.915
Item 8		0.872
Item 9		0.754
Item 10		0.845
Item 11	0.603
Item 12	0.669
Item 13	0.867
Item 14	0.920
Item 15	0.878
Item 16	0.909
Item 17	0.835
Item 18	0.869

Table 2. Pattern matrix: Factor loadings of the variables to each factor in the NASA-TLX.

	Component
	1	2
Item 1: Mental demand	0.830
Item 2: Physical demand	0.762
Item 3: Temporal demand	0.723
Item 4: Performance		0.958
Item 5: Effort	0.798
Item 6: Frustration	0.757

Figure 2. Time in seconds (0–1 sec: pre-stimulus period, 1–4 sec: speech presentation period, 4–6 sec: retention period) is shown on the x axis. Panel a shows mean (black line) pupil diameter during the 1-second pre-stimulus period. The shaded grey area represents ±1 SE. Panel b shows the mean change in pupil diameter, relative to pre-stimulus baseline during the speech presentation period and during the retention period. The shaded grey area represents ±1 SE. PPD: peak pupil diameter.

Table 3. Correlation coefficients (Pearson’s [r], 1-tailed significance) for the dependent (peak pupil diameter and pre-stimulus pupil diameter) and independent variables (PTA, age, VAS-1: tiredness/drowsiness, VAS-2: energy, VAS-3: exhaustion and physical fatigue, NASA-1: workload, NASA-2: performance, Task performance (RAU)) entered into the regression models.

	Peak pupil diameter	PTA	Age	VAS-1: tiredness/ drowsiness	VAS-2: energy	VAS-3: exhaustion and physical fatigue	NASA-1: workload	NASA-2: performance	Task performance (RAU)
Pre-stimulus pupil diameter	0.25*	–0.26*	–0.05	–0.32*	–0.07	–0.24*	–0.12	–0.03	0.29*
Peak pupil diameter		–0.11	–0.07	–0.19*	0.00	–0.22*	0.04	–0.04	0.08
PTA			0.20*	0.16	0.10	0.11	0.06	0.30*	–0.48**
Age				–0.01	–0.19*	–0.03	–0.15	–0.19*	–0.07
VAS-1: tiredness/ drowsiness					0.36**	0.57**	0.39**	–0.02	–0.11
VAS-2: energy						0.17	0.31*	–0.02	–0.11
VAS-3: exhaustion and physical fatigue							0.38*	–0.10	–0.06
NASA-1: workload								0.14	–0.00
NASA-2: performance									–0.21*

*Indicates that p was significant at 0.05 and ** indicates that p was significant at 0.001.

Figure 3. a. Relation between partial regressions for pre-stimulus pupil diameter and a sub-dimension of self-reported fatigue (VAS-1; tiredness/drowsiness), when hearing level and age are taken into account. Smaller pre-stimulus pupil diameter is associated with increased self-reported fatigue. b. Relation between partial regressions for pre-stimulus pupil diameter and performance, when hearing level and age are taken into account. Larger pre-stimulus pupil diameter is associated with increased performance accuracy.

Table 4. Model 2: Linear model predictors (PTA, age, VAS-1: tiredness/drowsiness, task performance) of pre-stimulus pupil diameter.

Model 2 (pre-stimulus pupil diameter)	b	SE b	β
Step 1
PTA	–0.01	0.01	–0.25*
Age	–0.002	0.01	–0.02
Step 2
PTA	–0.01	0.01	–0.20
Age	–0.003	0.01	–0.03
VAS-1: tiredness/ drowsiness	–0.10	0.003	–0.29*
Step 3
PTA	–0.003	0.005	–0.08
Age	–0.004	0.01	–0.04
VAS-1: tiredness/ drowsiness	–0.009	0.003	–0.28*
Task performance	0.02	0.009	0.25*

For model 2, R² = 0.06 for Step 1 (p = 0.08), R² = 0.15 for Step 2 (p = 0.008), R² = 0.19 for Step 3 (p = 0.04). *Indicates that p was significant at 0.05.