Carrosserie Akkermans

Sound-proof mobile hearing testing trailers

Located in the Dutch province of Noord-Brabant, Akkerman’s site in Oud Gastel turns out unique products for broadcasters, security services, blood banks, and health institutions. Merford is a long-standing supplier of acoustic materials to Carrosserie Akkermans. Our sound and vibration insulation plates keep ambient noise out of mobile testing units and special structures. Akkermans was recently commissioned by the Dutch Ministry of Defence to supply two mobile hearing testing trailers. Both trailers have four hearing test cells that meet extremely high sound insulation requirements. Merford was asked to provide its input on acoustics.

  • Carrosserie Akkermans
  • Industrial sector, Product manufacturers and suppliers, Traffic and transport

Supplier to the Royal Household

Having been active in its industry for over two hundred years, the Brabant-based company Akkermans holds the title of the oldest coachbuilder in the Netherlands. It has also been awarded the Royal distinction of Purveyor to the Royal Household. With a solid reputation for quality and reliability at home and abroad, Akkermans has built mobile dental practices, TV studios, medical units, and command centres for the police and military police. A large proportion of the company’s products are fitted with acoustic materials supplied by Merford, in order to achieve the desired level of sound insulation

Mobile hearing testing trailers

In 2020, Matlogco – the part of the Dutch Ministry of Defence responsible for the logistics and maintenance of all land systems of the armed forces, such as weapons and vehicles – asked Akkermans to build two mobile hearing testing trailers. The trailers were completed in early 2021. Each trailer has a waiting room and four hearing test cells in which Defence staff receive regular hearing check-ups.


Merford advised Akkermans on the acoustic design of the trailer and the testing units. Although the cells are directly adjacent to each other, a large set of sound-insulating measures – including the use of Agglomer, Isomat, and Regufoam – means they are acoustically almost completely isolated from the outside world and therefore from each other. The materials used prevent sound transmission between the test cells as well as ambient noise disturbance throughout the trailer. During the realisation process, Peter Lugtenburg (account engineer at Merford) performed noise measurements to verify that the trailer and the test cells met the set noise requirements. Sven Visser (account manager at Merford) is pleased with the collaboration with Akkermans and believes the project for the Ministry is a crowning achievement of the partnership. ‘When Merford is involved in a project at an early stage, that’s when we get the best results in terms of acoustics. The successful realisation of the mobile hearing testing trailers is perhaps the best example of this,’ says Visser.