PULSE Helps Hearing Aid Design

The Art of Hearing

Widex, pioneers in the hearing aid industry, and one of the world’s leading producers of high-quality hearing instruments, is a Danish company established in 1956 by Christian Tøpholm and Erik Westermann. Still family-owned, the company’s hearing instruments are marketed and distributed through an international network of distributors in 80 countries. In fact, some 97% of its production is exported.

The relationship between Widex and Brüel & Kjær goes back over many years, starting, in fact, around 1966, 39 years ago. So when Widex went in search for a new measurement platform, replacing the legendary Type 2012, it was only natural for them to contact Brüel & Kjær. The new instrumentation would not only have to accommodate Widex’s current needs but also provide them with a secure investment for the future.

The Challenges of Hearing Aid Design

The ultimate goal for hearing aid designers at Widex is to give hearing aid users the same opportunities for communication as people with normal hearing. Hearing aid designers have to take a long list of expectations and corresponding challenges into consideration, for example:

  • Improve speech intelligibility in noise
  • Reproduce nature’s sounds
  • Make soft sounds audible
  • Ensure that loud sounds are never uncomfortably loud
  • Ensure optimum music reproduction
  • Improve the users’ perception of their own voices

Although no one can claim that a hearing aid can restore “normal” hearing, recent advances in digital electronics, acoustics and audiological science have combined to make today’s instruments of greater help than ever before. Widex believe they have the products and the technology to help the hard of hearing to get the most out of everyday situations.

Keeping it In-house

Widex is a self-sufficient company, doing all of its research and development, testing, design and production in-house. This knowledge-based company is at the cutting edge of innovations within R&D of advanced hearing aid technology and considerable resources are earmarked for audiological and technological research ensuring state-of-the-art and reliable hearing instruments. Since the beginning, Widex, like Büel & Kjær, has been in the business of innovation from, for example, QUATTRO – the first hearing system making use of remote control, to Senso – the first fully digital in-the-ear hearing aid, and the award-winning Senso CIC completely-in-canal model.

So, when a company of Widex’s calibre decides that its current acoustic measurement platform can no longer fulfil its technical requirements, a huge effort is put into an intense, unrelenting investigation of all possible solutions on the market. Only the best is good enough.

Open and Flexible Solution Required

Widex’s main requirement was a solution able to make traditional standardised electroacoustic measurements performed on hearing aids, such as those performed successfully and for so many years using Type 2012 with dedicated software made by Widex. However, a technology-driven company such as Widex also required a solution that was open and flexible enough to perform measurements not previously possible with Type 2012. And measurements such as noise floor, directivity, EMC immunity, etc., were also considered to be equally important for Widex.

Introducing the PULSE Platform

Brüel & Kjær accepted the offer of presenting a solution fulfilling the necessary requirements, and introduced the PULSE platform to technicians, engineers and management at Widex. For a customer used to the user interface of Type 2012, it is easy to imagine how seductive the PULSE platform must have appeared. However, Widex’s Measuring Engineer R&D, Søren Christensen, responsible for finding the replacement, was initially cautious.

Shortly after the introductory meeting, we invited them to two days of PULSE training at Brüel & Kjær University where we were on-hand to provide all the support needed. The most important objective of this training was to ascertain to what extent a standard PULSE system could replace Type 2012. PULSE software SSR Analysis Type 7772 went a long way to satisfying the requirements, leaving only two things outstanding, tasks that could easily be resolved with the help of VBA programming.

Out with the Old, In with the New

Widex is the first customer to use PULSE 9.0, and in the months after delivery we’ve been following their progress closely, helping them to successfully get up and running with PULSE.

The future for Widex looks bright indeed. With untiring commitment to R&D, and now with the help of the PULSE platform, Søren Christensen and his colleagues can only succeed in their quest to break new ground and enhance and revolutionise hearing aid performance.

Measurements Made by Widex using PULSE

The PULSE system at Widex includes:
· PULSE Electroacoustic Test System
· PULSE Data Recorder
· PULSE Time File Management
· PULSE Data Manager, 5-user

It is used for:

Gain and output measurements on hearing aids
· Output sound pressure level response
· Full-on acoustic gain
· Frequency response
· Effect on gain with different battery impedance or voltage settings
· OSPL90 with different battery impedance or voltage settings

Measurement of amplitude non-linearities in hearing aids
· Harmonic distortion with different battery impedance or voltage settings
· Intermodulation distortion with different battery impedance or voltage settings

Internal noise generated in hearing aids
· 1/3-octave analysis

Induction pick-up coil measurements
· Frequency response
· Harmonic distortion

Automatic gain control measurements
· Input/output characteristics for sinusoidal signals
· Dynamic output characteristics for speech signals at different levels

Special Test Mode measurements
· Effect of band gain control on the basic frequency control
· Group delay
· Phase characteristics
· Amplitude characteristics

Real Mode Measurements
· Input/output characteristics at different bands and filter settings
· Attack and release time
· Oscillator frequency sensitivity and range
· Absolute gain
· Level check
· Microphone noise squelch at different bands

For further information please contact your local sales representative .

PULSE Helps Hearing Aid Design
We help our customers measure and manage the quality of sound and vibration in their products and in the environment

Brüel & Kjær Sound & Vibration Measurement A/S. P +45 77 41 20 00. F +45 45 80 14 05. info@bksv.com
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