PhD defence by Naim Mansour

On Friday 18 June, Naim Mansour will defend his PhD thesis: “Assessing hearing device benefit using virtual sound environments”.

Time: Friday 18 June, at 14:00

Place: Zoom / Building 303A, aud. 41

Important: Active registration:
- Building 303A, Aud. 41                                                                                                                               
Due to Covid-19 there is a restriction on the number of participants who are physically present in aud. 41. 
Therefore, if you wish to be present in the auditorium, please sign up here: 
All participants present in aud. 41 are responsible for complying with the applicable guidelines for distance, valid corona pas etc. 

- Zoom sign up:

Please be aware that the PhD defence may be recorded - This will also be informed at the beginning of the PhD defence. 


Principal supervisor: Professor Torsten Dau
Co-supervisor: Associate Professor Tobias May
Co-supervisor: Senior Officer Marton Marschall
Co-supervisor: Doctor Adam Westermann

Associate Professor Cheol-Ho Jeong, DTU Electrical Engineering
Research Associate Professor Virginia Ann Best, Boston University
Associate Professor Pavel Zahorik, University of Louisville School of Medicine

Chairperson at defence:

Associate Professor Bastian Epp


Hearing well in noisy everyday situations can be challenging, especially for people affected by hearing loss. Hearing devices try to restore a hearing-impaired person’s ability to accurately perceive sounds and understand speech. However, many psychoacoustic tests currently in use to evaluate speech intelligibility and hearing device performance do not take the acoustic properties of complex real-world sound scenes into account, typically relying on artificial target speech and background noise signals presented over headphones or small sets of loudspeakers. While these laboratory settings provide highly controlled and reliable results, they may not entirely reflect how people experience their real-world auditory reality.
The aim of this thesis was to increase the realism in psychoacoustic listening tasks inside controlled laboratory environments by employing “virtual sound environments”. A virtual sound environment, or VSE, consists of a spherical array of many loudspeakers and is capable of rendering physically accurate, spatial sound fields to a listener positioned in the center. By using VSEs in combination with spatially recorded real-world noise signals and spatialized target speech, realistic speech intelligibility tasks were designed and implemented. This included the development of a new, realistic method for measuring conversational speech levels. The tasks were shown to increase the difficulty of understanding speech compared to more artificial conditions, especially for hearing-impaired listeners. Hearing aids benefitted speech intelligibility most in the realistic conditions, which could be related to properties of the speech and noise signals and their effect on the hearing aid processing. A newly devised method for evaluating subjective, listener-reported hearing ability in a more controlled way was shown to be applicable inside realistic VSEs.
Overall, this thesis showed the ability of VSE-based laboratory environments to provide increased realism in psychoacoustic listening tasks, as well as render more ecologically valid results for both normal-hearing and hearing-impaired listeners. The development of increasingly realistic hearing and hearing device evaluation tests, using these environments, has the potential to increase the benefit these devices provide to users in their everyday life.


Fri 18 Jun 21
14:00 - 17:00


DTU Sundhedsteknologi


Zoom and build. 303A/aud. 41