Robot-controlled acoustic holography for hearing aid development

Identifying feedback due to leakage or vibration in hearing aids is a major challenge for hearing-aid designers. GN ReSound, a world leader in hearing aids and audiological instrumentation, commissioned a special turnkey solution from Brüel & Kjær. It features robot-controlled measurements coupled with Statistically Optimized Near-field Acoustic Holography (SONAH). It has stabilized development-time requirements and provided improved insights that build GN ReSound’s knowledge base.

Challenge

Achieving the device performance and gain needed in a new design was impossible to predict. It was particularly important to get away from traditional conformal mapping using hand-held arrays. The company needed a solution that could provide accurate, repeatable conformal mapping on the small scale they needed, and do so automatically.

Solution

A turnkey, robotic solution using our patented SONAH technology provided the accuracy and repeatability needed by GN ReSound. The solution consisted of three main parts: the robot holding the probe microphone, the robot controller and LAN-XI module, and the PC workstation.

Results

The new system enables sound intensity measurements to a precision that were impossible to carry out previously, and high-resolution mapping of small objects. Thanks to the precision of the system, the time needed for the development process – involving modelling, simulation, and verification – has been reduced by 20%. And repeatability has improved, too.