The Senso DIVA hearing aid from Widex
The company that started the digital signal processing revolution in completely-in-the-ear hearing aids in 1996 introduced their Senso DIVA™ in November, 2001.
The feature list for the Diva includes a chip size smaller than the Widex Senso (which was already one of the smallest in the industry), 15 channels and 15 frequency bands, Active feedback with no activation chirp, dual self-calibrating microphones, occlusion management, up to 4 programs, 20-35 dB reduction of wind noise, all with the goal of achieving "clear natural sounds".
15 channels and 15 bands
The 15 frequency bands can each be adjusted to the patient's hearing loss by in-situ measurement, using the hearing aid in the patient's ear as the tone generator. This gives precise fitting to the hearing loss characteristics. These 1/3 octave bandwidth channels can have cutoff slopes as steep as 50 dB per octave in the speech region if the hearing loss and background noise require it, and can adjust the bandpass slope depending on the need, becoming much less steep in quiet situations. Each of the channels has a compression threshold below 20 dB HL, with an input compression range of over 70 dB. Multi-segmental compression has the goal to make soft sounds audible, loud sounds comfortable, and to enhance speech sounds. Each channel includes a sound stabilizer and an anti-smearing system to enhance soft sounds after loud inputs and to preserve speech contrasts.
Self-calibrating dual-microphones are used to provide a directional system that allows the Diva computer to locate and reduce disturbing noise. The microphones continuously compare amplitude and phase with each other and adjust their outputs to compensate for changes, even changes due to usage. The microphone outputs are combined by the Diva computer to give an adaptive directional listening beam, which is used to reduce unwanted background noise, even noise that moves (like a passing car, or noise in a restaurant). A noise classification system adjusts the response of the microphones, to minimize noise, even working to reduce wind noise by 25 to 30 dB.
The Diva can be programmed to have up to 4 different listening programs (Microphone, MT, Telecoil and Music) in all models except the CIC case style. A push button changes from one program to another. Widex assumes that the M program will be used for nearly all situations, with all functions performed automatically. The alternate programs would be used to provide telephone coil capability, or perhaps a special music program. The Music program is derived from the original fitting with the signal processing parameters optimized for enhanced music appreciation.
Many different feedback cancellations systems have appeared in hearing aids over the years, but this one is different. The Diva uses two systems continuously: One analyzes the current feedback conditions and eliminates that feedback over a period of seconds. It subracts the estimated feedback signal, using much as 12 dB of gain to eliminate the path. The other system tracks abrupt changes in feedback and reduces the gain in the affected channel within 300 milliseconds to completely remove the "chirp" commonly heard when something comes close to your ear (like a phone or a party hug). The first system adjusts after a few seconds, and the quick acting system can relax. Together, these two system solve feedback problems without sacrificing gain. [Of course, you still have to put the hearing aid in your ear properly, and the case must fit your ear shape.]
The Diva allows the audiologist to adjust the frequencies below 600 Hz without changing any of the parameters at higher frequencies. This helps the audiologist reduce the occlusion effect.
The Widex Senso Diva is an exciting hearing aid that uses digital signal processing to provide a natural clear sound without artifacts or smearing of sounds. Widex calls this High Definition Hearing™.
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