J Am Acad Audiol 2019; 30(04): 264-272
DOI: 10.3766/jaaa.17060
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

The Task-Evoked Pupil Response in Divided Auditory Attention Tasks

Jennifer Baldock
*   Flinders University, Adelaide, South Australia, Australia
Sarosh Kapadia
*   Flinders University, Adelaide, South Australia, Australia
Willem van Steenbrugge
*   Flinders University, Adelaide, South Australia, Australia
› Author Affiliations
Further Information

Publication History

Publication Date:
26 May 2020 (online)



Successful processing of complex auditory information relies on the interplay between low-level sensory processing and higher-level cognitive processing. However, the extent to which specific auditory processing tasks rely on cognitive processing as opposed to lower-level sensory processing is unclear. The task-evoked pupil response (TEPR) can quantify the cognitive load that complex listening tasks elicit. Previous research by Koelewijn et al (2014) indicated that dividing attention across two sentences presented dichotically resulted in larger pupil dilation (indicative of greater cognitive load) compared with selectively attending to one. However, it was unclear whether the larger pupil dilation measured during the divided attention task were the result of dividing attention or were due to the increased memory demand inherent to that task.


The first aim of the current study was to address the above issue of memory demand by comparing pupil dilation between divided and selective auditory attention tasks, while keeping memory and response load constant. The second aim was to further clarify the influence of memory demands on TEPRs in these auditory tasks by comparing the pupil dilation recorded to measures of participants’ digit memory capacity.

Research Design:

A repeated measures design was used. Each participant undertook two selective and three divided auditory attention tasks, generated by varying the specific instructions before each condition of the dichotic digits test (DDT). In addition, participants completed forward and reverse digit span (DS) tasks.

Study Sample:

Thirty-one otologically healthy adults (aged 18–40 years) participated in this study.

Data Collection and Analysis:

A repeated measures analysis of variance was used to compare mean and peak pupil dilation between the selective and divided attention tasks. Spearman correlation analyses were used to examine potential relationships between DS scores and mean and peak pupil dilation elicited by the DDT conditions.


Participants demonstrated larger mean and peak pupil dilation (indicative of greater cognitive load) when they were required to divide their attention across both ears than when they were required to selectively attend to input in one ear. DS scores were not significantly correlated with mean or peak pupil dilation measures.


Auditory divided attention tasks involve significantly greater cognitive load than auditory selective attention tasks, even when memory demands are equal. In addition, mean and peak pupil dilation generated during the DDT are not significantly associated with digit memory capacity. The findings indicate that poor performance on tasks involving divided attention may be due to a cognitive deficit as opposed to an auditory processing deficit. Clinicians should consider this when using divided attention tasks in auditory processing assessments.

Presented in part at AudiologyNOW!, Phoenix, AZ, April 2016, and Audiology Australia National Conference, Melbourne, Australia, May 2016.


  • American Speech-Language-Hearing Association (ASHA) 2005 (Central) Auditory Processing Disorders. http://www.asha.org/policy/TR2005-00043/ . Accessed April 4, 2015.
  • Aston-Jones G, Cohen JD. 2005; An integrative theory of locus coeruleus-norepinephrine function: adaptive gain and optimal performance. Annu Rev Neurosci 28: 403-450
  • Beatty J, Lucero-Wagoner B. 2000. The pupillary system. In: Berntson GG. Handbook of Psychophysiology. 2nd ed. New York, NY: Cambridge University Press; 142-162
  • Benarroch EE. 2009; The locus coeruleus norepinephrine system: functional organization and potential clinical significance. Neurology 73 (20) 1699-1704
  • Bradshaw J. 1968; Pupil size and problem solving. Q J Exp Psychol A 20 (02) 116-122
  • Bregman AS. 1994. Auditory Scene analysis: The Perceptual Organization of Sound. Cambridge, MA: MIT Press;
  • Broadbent DE. 1971. Decision and Stress. London, United Kingdom: Academic Press;
  • Bryden MP. 1988. An overview of the dichotic listening procedure and its relation to cerebral organization. In: Hugdahl KE. Handbook of Dichotic Listening: Theory, Methods and Research. Suffolk, United Kingdom: John Wiley & Sons; 1-45
  • Cherry CE. 1953; Some experiments on the recognition of speech, with one and with two ears. J Acoust Soc Am 25 (05) 975-979
  • Diamond A. 2013; Executive functions. Annu Rev Psychol 64: 135-168
  • Einhäuser W. 2017. The pupil as marker of cognitive processes. In: Zhao Q. Computational and Cognitive Neuroscience of Vision. Singapore: Springer; 141-169
  • Faul F, Erdfelder E, Lang AG, Buchner A. 2007; G*Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods 39: 175-191
  • Gilzenrat MS, Nieuwenhuis S, Jepma M, Cohen JD. 2010; Pupil diameter tracks changes in control state predicted by the adaptive gain theory of locus coeruleus function. Cogn Affect Behav Neurosci 10 (02) 252-269
  • Hess EH, Polt JM. 1964; Pupil size in relation to mental activity during simple problem-solving. Science 143 (3611) 1190-1192
  • Kahneman D, Beatty J. 1966; Pupil diameter and load on memory. Science 154 (3756) 1583-1585
  • Kahneman D, Peavler WS, Onuska L. 1968; Effects of verbalization and incentive on the pupil response to mental activity. Can J Psychol 22 (03) 186
  • Kan A, Winn MB. 2016 Using pupillometry to investigate the better ear advantage. Poster session presented at: The 5th Joint Meeting of the Acoustical Society of America and Acoustical Society of Japan, November 28–December 2, Honolulu, HI.
  • Kimura D. 1961; Cerebral dominance and the perception of verbal stimuli. Can J Psychol 15 (03) 166
  • Koelewijn T, Shinn-Cunningham BG, Zekveld AA, Kramer SE. 2014; The pupil response is sensitive to divided attention during speech processing. Hear Res 312: 114-120
  • Koelewijn T, Zekveld AA, Festen JM, Kramer SE. 2012; Pupil dilation uncovers extra listening effort in the presence of a single-talker masker. Ear Hear 33 (02) 291-300
  • Kramer SE, Kapteyn TS, Festen JM, Kuik DJ. 1997; Assessing aspects of auditory hangicap by means of pupil dilation. Int J Audiol 36 (03) 155-164
  • Kramer SE, Lorens A, Coninx F, Zekveld AA, Piotrowska A, Skarzynski H. 2013; Processing load during listening: the influence of task characteristics on the pupil response. Lang Cogn Process 28 (04) 426-442
  • Kuchinsky SE, Ahlstrom JB, Vaden KI, Cute SL, Humes LE, Dubno JR, Eckert MA. 2013; Pupil size varies with word listening and response selection difficulty in older adults with hearing loss. Psychophysiology 50 (01) 23-34
  • Martin NA, Brownell R. 2008. TAPS-3: Test of Auditory Processing Skills. 3rd ed. Northumberland, United Kingdom: Ann Arbor Publishers;
  • Mattys SL, Davis MH, Bradlow AR, Scott SK. 2012; Speech recognition in adverse conditions: a review. Lang Cogn Process 27 7–8 953-978
  • McGarrigle R, Munro KJ, Dawes P, Stewart AJ, Moore DR, Barry JG, Amitay S. 2014; Listening effort and fatigue: what exactly are we measuring? A British Society of Audiology Cognition in Hearing Special Interest Group ‘white paper’. Int J Audiol 53 (07) 433-445
  • Moore DR. 2015; Sources of pathology underlying listening disorders in children. Int J Psychophysiol 95 (02) 125-134
  • Musiek FE. 1983; Assessment of central auditory dysfunction: the dichotic digit test revisited. Ear Hear 4 (02) 79-83
  • Parkinson SR. 1974; Variability and control in dichotic memory. J Exp Psychol 102 (01) 67
  • Piquado T, Isaacowitz D, Wingfield A. 2010; Pupillometry as a measure of cognitive effort in younger and older adults. Psychophysiology 47 (03) 560-569
  • Schow RL, Seikel JA, Chermak GD, Berent M. 2000; Central auditory processes and test measures: ASHA 1996 revisited. Am J Audiol 9 (02) 63-68
  • Simpson H. 1969; Effects of a task-relevant response on pupil size. Psychophysiol 6 (02) 115-121
  • Simpson H, Hale SM. 1969; Pupillary changes during a decision-making task. Percept Mot Skills 29 (02) 495-498
  • Sirois S, Brisson J. 2014; Pupillometry. Wiley Interdiscip Rev Cogn Sci 5 (06) 679-692
  • Tomlin D, Dillon H, Sharma M, Rance G. 2015; The impact of auditory processing and cognitive abilities in children. Ear Hear 36 (05) 527-542
  • van Rijn H, Dalenberg JR, Borst JP, Sprenger SA. 2012; Pupil dilation co-varies with memory strength of individual traces in a delayed response paired associate task. PLoS One 7 (12) 1-8
  • Winn MB. 2016; Rapid release from listening effort resulting from semantic context, and effects of spectral degradation and cochlear implants. Trends Hear 20: 1-17
  • Winn MB, Edwards JR, Litovsky RY. 2015; The impact of auditory spectral resolution on listening effort revealed by pupil dilation. Ear Hear 36 (04) e153-e165
  • Zekveld AA, Kramer SE, Festen JM. 2010; Pupil response as an indication of effortful listening: the influence of sentence intelligibility. Ear Hear 31 (04) 480-490
  • Zekveld AA, Kramer SE, Festen JM. 2011; Cognitive load during speech perception in noise: the influence of age, hearing loss, and cognition on the pupil response. Ear Hear 32 (04) 498-510