Who are we?
Sonion is a global leader in the market for transducers used in the hearing aid and audio industry, and our ambition is to grow from this strong core. Our vision is: We help the world listen. We are dedicated to enhancing the quality of life for people who rely on hearing products. Are you passionate about making a difference in people’s lives? So are we!
The Sonion Group develops, manufactures, and sells product solutions to customers who manufacture hearing instruments and other acoustic solutions. Sonion Nederland B.V (Sonion NL) is the main R&D center within transducers and modules, but Sonion NL also has sales supportive activities such as Application Engineering, CQS and administrative support functions. Sonion has facilities in Denmark, the Netherlands, Vietnam, the Philippines, USA and China, wherefrom our (more than 6000) colleagues work together across all locations.
At Sonion we believe in the importance of investing in new talent. We want to introduce students to an environment where they are given responsibility and the freedom to develop their skills. In Hoofddorp you will join approx. 100 of our colleagues as we design new products for the hearing health and pro audio market. We offer internship positions every semester in various departments and are always on the lookout for new talent to join our team.
The department
The recently established Modeling and Simulation Department at Sonion has a young and rapidly growing team with the goal to model and design innovative products for the hearing aid and pro-audio industry, such as miniaturized loudspeakers and other transducers used also in many modern consumer electronics products like smart phones, ear buds, tablets. In case of hearing aids, transducers are the main active components, and their behavior is crucial for the hearing aid performance. Therefore, a good dynamic model able to predict the behavior of the transducer under different conditions is required in order to test new designs, optimize the sound quality and reduce the product size.
Possible Projects – Balanced armature receivers with high sound pressure levels and low distortion.
Balanced armature (BA) receivers are miniaturized loudspeakers used in hearing aid instruments, earphones, and hearables. A typical design of a BA receiver includes an armature (metal strip) that is placed between two permanent magnets and a coil that is wound around the armature. The armature tip is positioned exactly in the center between the magnets and the magnetic fields in the gaps between the armature and the magnets are equal (hence the name, balanced armature). The current that runs through the coil – representing the audio signal – will inject a magnetic flux into the armature, causing the difference in magnetic field in the two gaps between the armature and magnets. This breaks the magnetic balance and creates magnetic force acting on the armature tip and sets it in motion. A drive pin connected to the armature on one end moves the membrane (diaphragm) on the other end producing sound.
During the development and manufacturing phase of the electroacoustic transducers, improving the transducer performance in terms of high sound pressure levels (SPL) and low total harmonic distortion (THD) is a clear goal for the developers in the industry.
BA receivers operate in multiple physics domains. This makes them both interesting and complex. Because of its complex non-linear nature, it is important to understand their limitations in producing maximum sound output with acceptable low levels of distortion (THD within 1-2%). Typically, magnetic saturation and airgap, that is the distance between armature and magnets, can limit the maximum armature displacement, hence the maximum SPL.
In this project the main goal is to propose and develop BA receiver concepts for armature and magnet shells that can maximize the output and keep low levels of THD. For this goal, part drawings, subassembly designs, finite element-based simulations and prototypes will be used.
Frequency responses (dBSPL) and THD of the prototypes with the proposed concepts will be measured for the entire audio frequency range (20 Hz – 20 kHz). The measurements will be characterized by different voltage drive levels that can initiate magnetic saturation in the receiver armature and by acoustic loads that correspond to different positions of the balanced armature receiver in the hearing aid or earbuds
Your profile
- Currently studying mechanical engineering, electrical engineering and/or physics at a Masters level;
- Knowledge of engineering processes/principles;
- Ability to write technical documentation;
- Capable of thinking on a system level as well as on component level;
- Familiarity with one (or more) of the following topics: acoustics, finite element methods, electromagnetism, computational mechanics;
- Easy learner (to use new FEM-based softwares (COMSOL) or SPICE simulators (OrCAD, LTSpice);
- Basic knowledge of Mathworks Matlab;
- Proactive, solution-oriented, and willing to take ownership of responsibilities;
- Not afraid to think “outside of the box”;
- Fluent in English, written and spoken. Sonion is an international company and with the Hoofddorp office we have colleagues from all over the world. Basic/fluent Dutch is a plus.
Equally important to your knowledge and experience, are you as a person. We are looking for a person, who is proactive, eager to learn, hands-on and results driven. You can also interact effectively with people from all backgrounds.
Our offer
- Internship starting September 2025 lasting for 5-6 months with possible extension;
- Your own workspace with all the hardware you will need;
- Compensated travel expenses if you don’t have your Study OV card;
- €605 monthly internship allowance;
- Flexible workhours;
- Free parking;
- An office located a 5-minute walk away from Hoofddorp train station.
More importantly, we offer you a professional work environment that gives you the opportunity to steadily further develop. In this project, you will get a lot of responsibility and chances to use your knowledge in the field. You and your supervisor will regularly reflect on your work. Sonion is an international and inclusive organization where it is easy to connect with colleagues. So, what are you waiting for? Apply now!
Further information and application
Did this spark your interest? Email us your motivation letter and your CV in English to jobsatsonionNL@sonion.com. Please specify your internship dates and the type of internship, that can be an orientation or a graduation internship.