Designing a hearing aid with excellent acoustic properties while accommodating potentially conflicting requirements. For example, customers now expect their hearing aids to seamlessly connect to their phones via Bluetooth®, which places even greater demands on battery capacity.
When we think of ‘engineering marvels’, our minds often conjure images of grand structures such as bridges, spacecraft, and airplanes. Yet, we sometimes overlook the quieter marvels that lack the prominence of these aforementioned feats. The contemporary hearing aid epitomises one such marvel, representing the culmination of rigorous and devoted development. It emerges as one of the most sophisticated engineering achievements to date.
With over 1.6 billion people globally experiencing hearing loss, it’s no wonder that top engineering talents are drawn to this fiercely competitive field. At the forefront is WS Audiology, housing several brands under its umbrella, including the premium hearing aid brand Widex. Boasting a dedicated team of more than 12,500 professionals, WSA is committed to continuous innovation, steering the course of auditory technology’s future.
An HBK system consisting of a multichannel data acquisition analyzer platform with LAN-XI ‘hardware’ to verify the acoustic performance of new hearing aids.
Creating a hearing aid that restores natural hearing for individuals with hearing loss is the primary goal for WSA. The challenge lies in designing a hearing aid that encompasses:
These requirements often conflict with one another; for example, achieving a smaller size and incorporating Bluetooth® may result in reduced battery life. Therefore, striking the right balance among these specifications is a critical issue for WSA, necessitating numerous iterations during development. Ultimately, any firmware, hardware, or software changes must undergo rigorous acoustical verification testing to meet WSA’s high standards.
WSA caters to two distinct customer groups: end-users (patients) and hearing clinics. These two groups have different criteria for evaluating a good hearing aid. Hearing care professionals possess audiological knowledge and can set up and tune the hearing aid for optimal assistance to the end-user. End-users utilise the hearing aid and its associated ecosystem to enhance their hearing in various listening environments. For instance, individuals with hearing loss often struggle to hear high-frequency sounds, such as birds chirping, which may become inaudible to them. One solution is frequency shifting, a technique that lowers the pitch of high-frequency sounds like bird chirps to a range where hearing-impaired individuals have better sensitivity. While this frequency alteration may sound unnatural to those with normal hearing, it can be a joy for hearing-impaired individuals to regain the ability to hear such sounds.
As a premium brand, WSA places immense importance on providing customers with the ultimate hearing experience. Therefore, thorough and dependable testing processes are essential to ensure the effectiveness and reliability of their products.
Kenneth Muff Lassen is part of the acoustic verification team at WSA. Upon the completion of product development, each product undergoes a final standardised test conducted at the desktop test stands.
These test systems are crucial for evaluating both hardware and software components. WSA not only manufactures hearing aids but also develops software that is used to tune the hearing aid settings according to individual hearing needs. Thus, the product encompasses not just the physical hearing aid but also the associated software. Typically, an audiogram is used, visually showing hearing loss as a function of frequency.
WSA employs test equipment as calibration systems and their primary interest lies in absolute values. Specifically, WSA wants to verify that when the software is configured to output, for instance, 60 dB, the hearing aid will indeedgenerate 60 dB within the user’s ear. The automatic test examines all scenarios of the fitting software with the hardware in the loop, ensuring comprehensive evaluation and validation.
WSA upholds uncompromising standards for acoustical performance and consequently has made significant investments in a high-quality measurement system with quality control an absolute priority. The HBK automatic test system proves invaluable, allowing comprehensive testing of both software and hardware in a single operation.
A system that is not only an invaluable and powerful tool to accelerate product development and for real-time measurement during troubleshooting, but also reflects their high standards to customers and competitors alike.
WSA has two test setups for evaluating hearing aids where an anechoic test box containing a hearing aid is positioned in front of a speaker. An HBK LAN-XI data acquisition module generates a signal,such as sweep, white noise, and International Speech Test Signal (ISTS), that is transmitted via a power amplifier to the built-in speaker within the anechoic test box. A reference microphone is located to the right of the hearing aid. The hearing aid’s loudspeaker (receiver), typically situated inside the user’s ear during real-world use, is for testing purposes positioned in a 2cc coupler or ear simulator (711 coupler).
The ear simulator simulates the human ear’s response to the hearing aid, accounting for the acoustic impedance of the ear. The reference microphone captures the sound signal to which the hearing aid is exposed. Additionally, the coupler incorporates a built-in microphone that measures the output sound produced by the hearing aid. This signal is then transmitted to the Type 3160-A-042 LAN-XI system, which further sends it to PULSE for analysis.
The hearing aid undergoes several acoustic tests, including:
Input and output measurements are saved in ‘PULSE file ASCII’ format and are subsequently compared and plotted using MATLAB.
WSA’s products consist of a chain of components, and if a hearing aid experiences issues, the root cause can stem from a number of different sources:
Changes in design have the potential to adversely affect acoustic characteristics. When an acoustical verification test fails, identifying the root cause needs to be determined so that the issue can be solved. Since problems can arise at different points in the measurement chain, real-time measurement during troubleshooting becomes essential. In this context, PULSE serves as a powerful tool.
WSA upholds uncompromising standards for acoustical performance and consequently has made significant investments in a high-quality measurement system with quality control an absolute priority. The HBK automatic test system proves invaluable, allowing comprehensive testing of both software and hardware in a single operation. Moreover, this system facilitates efficient troubleshooting: when implementing a change, measurements can be paused, enabling a thorough diagnosis of any issues that arise.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, MicroStrain and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
