How It’s Made | The Development of a Hearing Aid

By Charlotte T. Jespersen, M.A.

Hearing aid development is a complicated process that involves much more than simply putting a case around electrical components. The process involves a cross-disciplinary team of experts – including an audiologist, acoustician, electronics engineer, mechanical engineer, industrial designer, algorithm programmer and product manager, amongst others – working together to create a hearing aid that fits a certain market need.

The Role of the Audiologist
Because audiologists are among those who best understand the needs of a hearing aid user, they are involved in nearly all stages of the development process. These stages include research, concept development, detailing of product requirements and ensuring proper functionality. The audiologist works with the cross-disciplinary team to clarify and communicate the needs of both the end-user and the dispenser.

The Role of the Product Manager
The product manager is responsible for understanding the hearing aid market and providing market input to the cross-disciplinary team. This information, coupled with end-user and dispenser needs provided by the audiologist, guides the technical professionals in creating a product strategy.

The Role of the Engineer
After hearing aid requirements have been defined and a product strategy has been created, development is initiated of the sound processing features (algorithms), hardware, acoustic calibrations and fitting software. The development process is not a step-by-step process, with one layer being added at a time. Instead, the process consists of multiple development processes that are conducted at the same time and are then combined at different phases during the process.

The Role of the Designer
While the engineers are busy creating, testing and validating sound processing features and acoustic algorithms, the industrial and mechanical designers are working on designing a discreet and attractive product that accounts for the makeup of the ear. The designers are dependent on other team members to provide information concerning the size and necessary position of all the hearing aid’s internal components. Hardware development is like software development in that it involves concepts that are tested and revised numerous times. The audiologist is involved in this process too, providing input on things such as size and placement of push buttons and operation of the battery door.

The Role of the End-User
End-user testing at various stages of the process is critical to success. The hearing aid is tested on individuals with hearing loss who could potentially benefit from the technology being developed. Testing begins after the sound processing features have been tested, refined and verified. The product is evaluated using either existing hearing aid hardware or a prototype of the hardware under development. Multiple iterations of the sound processing features are tested during the development process.

The expertise of many disciplines is used in collaboration to develop a hearing aid that satisfies many needs, from audiological benefit to mechanical durability. Continuous testing of hearing aid prototypes, up until and including the final product, is required to ensure product quality. Hearing aids and sound-processing features are typically tested by audiologists on hundreds of ears before being put on the market. This testing helps to ensure that the product functions properly in the real world.