Skip to ContentSkip to Navigation
About us Latest news News News articles

New speech valve a boon for laryngectomy patients

06 June 2012

An automatic speech valve based on a new technique helps more l aryngectomy patients to speak more naturally and with less effort. Researcher Ward van der Houwen of the UMCG is behind the development of this new speech valve. Van der Houwen thinks that the new valve will improve the quality of life of l aryngectomy patients. Although automatic speech valves already exist, these are rarely actually used. Van der Houwen’s research looked into the reasons why. The University of Groningen will award Van der Houwen a PhD for his research on 13 June 2012.

L aryngectomy patients can no longer speak. When a larynx tumour is removed, the patients may have survived throat cancer, but have paid a high price. They can no longer smell, they have to breathe through an opening in their neck and they are unable to speak. A surgical connection between the trachea and oesophagus enables them to produce sounds by exhaling through their oesophagus. They can then speak using this sound as a surrogate vocal cord. Van der Houwen investigated which aids these patients use and what difficulties they encounter when using them.

A stoma adhesive patch that fits

Van der Houwen first measured the size and shape of the stoma opening of 191 l aryngectomy patients all over the world and determined how well the patches and other aids fit. He discovered that the existing patches on which filters and speech valves are mounted do not sit properly because they are flat, while the stoma openings are funnel-shaped. ‘Surgeons try to change the shape of the stoma opening, but the first step should be to change the shape of the patches,’ says Van der Houwen. He consequently set about designing just such a patch.


The ideal solution turned out to be the use of a flexible material - silicone rubber - for both the patches and the speech valve. The flexible rubber allowed him to design totally new aids. Rubber parts can be folded inside out, and because the outside then becomes the inside, it is possible to create a complex valve from a simple mould. ‘This innovative technique using silicone rubber allowed me to reduce the fourteen components in the traditional speech valve to just one in this new version. This makes this speech valve available to many more patients,’ Van der Houwen explains.


Van der Houwen worked with many different parties on this research project. ‘Patients, physicians, manufacturers, various research departments and more than 40 interns and graduation project students participated. It was an intense and incredibly fun process in which all the participants were deeply involved.’ Van der Houwen extensively tested the prototypes on the participating patients. ‘They enjoyed helping with the project and some had very useful suggestions for the design. It is important that patients see that they can play a role in the development of such aids, because they, after all, are the experts,’ says Van der Houwen. The speech valve he developed, called the iValve, is now being developed into a market-ready product by the German firm Servona. ‘That was always the goal of this research. And we succeeded doing just that.’

Curriculum vitae

Ward van der Houwen (Gouda, 1973) studied Industrial Design Engineering at TU Delft. He conducted his research at the Kolff Institute, where he founded the medical product development lab, and the ENT department, both part of the University Medical Center Groningen. The research was funded by the Nuts-Ohra foundation, the UK company Technovent, the Tonny and Luit Sol foundation and the Stol-Hoeksema family foundation. The title of his thesis is ‘Development of a handsfree speech valve for laryngectomy Patients.’ Van der Houwen now works as an independent consultant and product developer. For more information, pictures and videos, see and

Last modified:13 March 2020 01.49 a.m.
View this page in: Nederlands

More news

  • 27 May 2024

    Four honorary doctorates awarded by the UG

    On Friday, 24 May, the UG awarded four honorary doctorates to Dr Kate Crawford, Dr Tedros Ghebreyesus, Gerrit Hiemstra and Prof. Mariana Mazzucato. The presentation took place in the Aula of the Academy Building and was part of the university's...

  • 24 May 2024

    Lustrum 410 in pictures

    Lustrum 410 in pictures: We are already over half way through our lustrum! Enjoy a few photos of the lustrum so far.

  • 21 May 2024

    Results of 2024 University elections

    The votes have been counted and the results of the University elections are in!