Remember when hearing aids had four components: microphone, amplifier, receiver and battery? Explaining hearing aids was much simpler. Today’s hearing instruments come with many more options and technology. Where does one begin the explanation? ReSound’s Jennifer Groth, M.A., and John Nelson, Ph.D., breakdown signal processing into four “chapters”: Model, Clean, Balance, and Stabilize at the 2013 AudiologyNow! conference. This provides audiologists with a structure to discuss amplification and technology with the end user.
Model:
- WARP Processing: Models the signal to replicate the way the natural ear breaks down sound into distinct pitches. It also forms the core for other sound treatment and is the foundation for clear and distinct sound. The benefit derived is near-zero distortion and remarkable purity.
- Environmental Classifier: Analyzes the sound environment then models the signal to replicate that environment in digital format as well as identifies how loud or soft sounds are whether they are speech or other and where they originate. The benefit derived is a foundation that allows us to balance the signal into fine nuances.
Clean:
- Noise Tracker II: Eliminates just enough background noise for comfortable listening with reduced effort and allows speech signal to remain intact and natural sound quality is maintained. Benefit: increases end user comfort in noisy listening situations without compromising speech understanding.
- Expansion: Lowers the noise floor of the hearing instrument, ensuring best sound quality in quiet situations.
- Windguard: uses a new sound processing technique which utilizes inputs from both microphones together to recognize and reduce annoying wind noise.
Balance:
- WDRC: Makes soft sounds audible and loud sounds comfortable for a perfect balance between audibility and comfort. It also personalizes for the individual’s hearing profile.
- Directional Mix Processing: Separates and balances low/high pitches enabling differential treatment of speech and background noise and improves speech understanding in noise in all directional modes.
- Environmental Optimizer (Binaural Fusion): Balances the volume level of the sound environment relative to the individual’s needs.
Stabilize:
- DFS Ultra: Stabilizes the signal by suppressing feedback through phase cancellations and built in WhistleControl and provides sufficient gain without introducing artifacts or compromising sound quality. The benefit derived is that the patient can gain confidence using the telephone, embracing, wearing hats and so on.
In addition, today, we also need to consider connectivity. Connectivity allows for interaction between hearing instruments and allows receiving of audio signals from remote transmitters to increase signal-to-noise ratio for the listener. Examples include the ReSound Unite Mini Microphone which allows direct audio streaming up to 7 meters in range of the hearing aids with a fixed clip or lanyard.