Digital Hearing Aid Technology

The first digital hearing aids were introduced to consumers in 1987. Two manufacturers produced devices that were too big and the batteries were not strong enough to do the job, so they quickly disappeared. Fast forward another ten years. In 1997 new digital hearing aids were introduced in different styles, which could be worn behind the ear, as well as in the ear canal. Consumers and technicians thought they were great even though they were expensive. The 1997 hearing aids provided digital hearing technology with the success it needed to move into the twenty-first century.

Digital hearing aids are considered state-of-the-art instruments these days. Digital Signal Processing has come a long way in 22 years. Digital hearing aids are not superior to analog hearing aids because they are digital. Digital means that the analog waveform is converted into numbers for processing purposes. Digital technology gives manufacturers the ability to create hearing aids with enhanced processing features thanks to Digital Signal Processing. That means that digital hearing aids have some major advantages over analog hearing aids, which include Digital Feedback Reduction, Digital Noise Reduction and Digital Speech Enhancement.

Digital Feedback Reduction helps with the occasional feedback a consumer experiences with jaw movements or with objects that are nearby. A notch filtering and cancellation system is used to reduce or eliminate moderate feedback. Digital Noise Reduction is still in the fine tuning stages. It does reduce noise and improves speech recognition when there is no fluctuating noise in the background. DFR can also be used with directional microphones to remove background noise from behind, as well as to the sides of the consumer. Digital Speech Enhancement processing is a new technology that increases the intensity of different segments of speech and it also enhances as well as identifies speech based on temporal or spectral content.

Directional microphones combined with Digital Signal Processing calibrate the microphones and improve the signal-to-noise ratio, as well as reduce the noise produced by the directional microphones. All types of digital hearing aid have the ability to process as well as generate sound. Those abilities are used in threshold and loudness testing, so individuals can be fitted for specific hearing aids that will work for their situation. DSP helps streamline the fitting process, which reduces the need for external equipment.

Analog hearing aids are less expensive and they can be programmed for different levels of hearing loss and they can make sounds louder, but they lack the versatility of digital models in terms of distinguishing noise and speech. They don’t block out background noise which is a major issue with hearing aid users. There are some people who prefer analog at this point in time because there are still some issues with certain digital models. Most of those issues will be corrected in a short period of time thanks to the rapid movement of digital technology.

The time will come when digital hearing aids will completely replace the analog instruments. Advancements in DSP technology continue to amaze and excite the hearing aid industry. Amplifying hearing using Digital hearing aid technology will help a lot of people hear a pin drop again.