Where did the idea of developing hearing aids come from? As with most technological developments, there is no easy answer to this question. At Bernafon, our development philosophy usually comes from what we have done in the past, what is discussed in the audiology research literature, and sometimes even comes from our imagination.
Sometimes, due to technical limitations, we need to adjust our ideas to get what we want, but in many cases we do. A good example is amplifying speech in the presence of background noise. We have been discussing this issue for many years, and I want to explain it to you in the context of the dynamic gain control (DAC) function in DECS, which is the latest technology in our Bernafon hearing aids.
Hearing-impaired people with inner ear hearing loss have impaired speech perception. The resolution of the cochlea will decrease, which can be overcome by increasing compression. With the loss of outer hair cells, the active compression system weakens, and with the loss of inner hair cells, information transmission weakens.
In many cases, compression may not be desirable, such as background noise. So how do we view the environment and then turn off the compression system if necessary? Our first attempt to change compression based on the environment was in 2009 using a feature called dynamic contrast.
After selecting this option, the instrument will attenuate to different gain settings when the voice is detected in the noise. Essentially, compression is reduced. One year later, we can use the environment optimizer to select different environments for hidden instruments.
In the case of interference noise, such as silence or background noise (no speech), if this specific environment is recognized, the gain can be adjusted. These features are very popular, but we are starting to think more about other features that cause more problems. He wanted to know what would happen if a person had certain difficulties in understanding language in several situations.
Second, we also consider environments where one person’s definition of noise or speech in noise may not match another person’s definition. Finally, we are concerned that the noise of the compression system will be amplified by the noise cancellation system and the directional microphone. Development is also static-we can only make one set of gain settings.