Dorothea Wendt

Scientist, PostDoc

LISTEN contributed to a worldwide process associated with a paradigm shift in the field of hearing science. This shift is related to the change in diagnostic methods used to evaluate the benefits of hearing aids.

Hearing impairment is a leading cause of disability worldwide. As people age, their hearing ability deteriorates inevitably. Listening effort, distress, lack of energy, fatigue, increased levels of need for recovery and sick leave are notorious consequences of age-related hearing loss.

Research within the EU funded project LISTEN was developing tools to evaluate and interpret the extent to which hearing solutions, such as hearing aids 1) improve performance in terms of speech understanding, and 2) reduce the listening effort required to perceive the speech.

The project also aimed at further developing the method of pupillometry by examining additional pupil reflex parameters than the ones previously used in Audiology research.

About the LISTEN project

LISTEN was an EU-funded project which ran between 1/10/2013 until 30/9/2017. The project was a collaboration between Eriksholm Research Centre, VU University medical center, Amsterdam, and National Center for Rehabilitative Auditory Research, Glasgow. Two Early Stage Researchers (ESRs), namely Barbara Ohlenforst and Yang Wang, were trained at the VU and seconded to Eriksholm Research Centre, where we provided them with specialized training.

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Main findings

Researchers developed a new approach for evaluating the extent to which hearing aids can reduce listening effort. Until now, pure-tone audiometry -sometimes combined with traditional speech recognition measures- has been used for the development of hearing aids. 
Since traditional speech recognition measures lack the sensitivity to be applied under these easier acoustical conditions, such as for speech understanding in quiet or at high Signal-to-Noise Ratios (SNRs), they cannot always adequately be used as an outcome for research on the benefit of a hearing aid. 
Within LISTEN, the pupillometry method was developed further as an alternative form of measurement revealing how listening effort is modulated across the entire range of day-to-day listening situations. From acoustically challenging towards easier listening situations.

Rather than utilizing conditions representing difficult and noisy listening situations in daily life, LISTEN provided knowledge and evidence for more realistic (that is easier and quieter) listening situations. A novel finding was that while hearing aids increase speech understanding in difficult listening situations, they also significantly reduce listening effort under easier listening conditions. 

The underlying mechanisms of the pupil dilation response were further unraveled in studies measuring the pupil light reflex. These studies revealed that an individual’s level of fatigue influences the level of effort one can exert, which revealed a breakthrough in our understanding of the mechanisms behind listening effort and the pupil dilation response.

Further reading:

Ohlenforst B, Zekveld A, Jansma E, Wang Y, Naylor G, Lorens A, Lunner T, Kramer S (2017). Effects of Hearing Impairment and Hearing Aid Amplification on Listening Effort: A Systematic Review. Williams And Wilkins Ear and Hearing. doi:10.1097/AUD.0000000000000396, pmc:PMC5405775.

Ohlenforst B, Wendt D, Kramer S, Naylor G, Zekveld A, Lunner T (2018). Impact of SNR, masker type and noise reduction processing on sentence recognition performance and listening effort as indicated by the pupil dilation response. Elsevier 0378-5955 2018. doi:10.1016/j.heares.2018.05.003.

Ohlenforst B, Zekveld A, Lunner T, Wendt D, Naylor G, Wang Y, Versfeld N, Kramer S (2017). Impact of stimulus-related factors and hearing impairment on listening effort as indicated by pupil dilation. Hearing Research (ISSN: 0378-5955), vol: 351, pages: 68-79. 

Wang Y, Zekveld A, Naylor G, Ohlenforst B, Jansma E, Lorens A, Lunner T, Kramer S (2016). Parasympathetic Nervous System Dysfunction, as Identified by Pupil Light Reflex, and Its Possible Connection to Hearing Impairment. PUBLIC LIBRARY SCIENCE PLoS ONE, Vol 11, Iss 4, p e0153566 (2016) 2016. doi:10.1371/journal.pone.0153566, pmc:PMC4835104

Wang Y, Zekveld A, Wendt D, Lunner T, Naylor G, Kramer S (2018). Pupil light reflex evoked by light-emitting diode and computer screen: Methodology and association with need for recovery in daily life. P L o S One (ISSN: 1932-6203), vol: 13, issue: 6, 2018.

Wang Y, Naylor G, Kramer S, Zekveld A, Wendt D, Ohlenforst B, Lunner T (2017). Relations Between Self-Reported Daily-Life Fatigue, Hearing Status, and Pupil Dilation During a Speech Perception in Noise Task. Ear and Hearing (ISSN: 0196-0202), vol: 39, issue: 3, pages: 573–582, 2017