Listening effort in the European Population (LISTEN) (WC2013-030)


Starting date: 01/03/2014

Research questions addressed in LISTEN:

a)      What are the effects of hearing loss on speech intelligibility, the pupil dilation and pupil light reflex?

b)      What is the relation between the pupil dilation, pupil light reflex and (long-term) stress, fatigue, need for recovery from stress, and activities in daily life as assessed by questionnaires?

c)       What is the influence of different hearing aid technologies on speech perception and the peak pupil dilation during listening?

d)      What is the relation between verbal inference making, working memory, speech perception, and the peak pupil dilation and pupil light reflex?


a)      Previous studies have shown an interaction between hearing loss, speech intelligibility and the pupil dilation during listening (Kramer et al., 1997; Zekveld et al., 2011). Based on these results we expect slightly smaller task-evoked pupil dilations in listeners with hearing loss than those of age-matched listeners with normal hearing, particularly at difficult intelligibility levels. However, we also expect smaller pupil light reflex in listeners with hearing loss, reflecting effects of long-term stress (Hasson et al., 2009).

b)      Hearing related stress has been associated with reduced parasympathetic activation (Hasson et al., 2009). We expect that listeners who report higher levels of stress and fatigue, higher need for recovery during daily life and fewer activities in daily life will have relatively small pupil light reflex .

c)       High levels of long-term stress may be associated with larger pupil dilation (as parasympathetic activation is smaller).

d)      The application of hearing aid technology will alter the pupil dilation.

e)      We expect that the pupil dilation will be larger in listeners with good cognitive skills (e.g. Grady, 2012; Zekveld et al., 2011).