Understanding Hearing Aid Technology

Hearing aid technology has advanced dramatically over the last several years. Just as music and television has transitioned from an analog to a digital format, hearing aids themselves have transitioned to digital. Digital hearing aids utilize advanced microchips and digital circuitry to control and amplify sounds.

The cost of hearing aids is influenced by:

• Microphones
• Feedback management
• Noise reduction features
• Channels
• Gain for soft sounds (compression threshold)
• Data-logging

Microphones

Adaptive microphones make adjustments for the person wearing them based on the listening situation. For example, if the speaker is in front of the user, the microphone zooms to the front. If the speaker is on the side, the microphone pattern zooms to the side. In many ways, these microphones "think" intelligently based on the speakers that surround the hearing aid user, and make communication easier in difficult listening situations.

Feedback management

Today's hearing aids also offer feedback management, which means that they contain mechanisms to help control feedback with active feedback cancellation technology that does not reduce gain. This type of feedback manager can increase the gain for soft sounds in the higher frequencies, which means better speech recognition for soft speech, a benefit for patients with severe hearing loss as well as patients with good low-frequency hearing that requires a vent.

Number of independent channels

To be considered a premium hearing aid, the processor inside the hearing aid must have at least 10 independent channels. This is important for patients who experience a steep drop in hearing in the higher frequencies. Indirectly, this feature also decreases the risk of feedback as well.

Gain for soft sounds

The gain for soft sounds within a hearing aid is determined by what is known as the compression threshold of its circuit, which can range from 0dbHL to 40dbHL. Softer speech sounds influence the degree of recovery in the speech region of the brain, which is a good predictor of understanding speech. The lower a hearing aid's compression threshold, the more gain for soft sounds can be realized.

Noise reduction features of the processor

The capacity of a hearing aid to reduce noise makes it much easier to communicate in noisy environments, especially when the hearing device is coupled with an adaptive microphone. Noise reduction features are most beneficial when the noise is a "steady state" noise such as a car engine, fans, dishwashers, etc.

Because noise reduction circuits are unique to each hearing aid manufacturer, their quality and effectiveness can vary from manufacturer to manufacturer and brand to brand. Patients should be aware the situations in which noise reduction features are least effective is in reducing ordinary background noise.

Data logging

A new feature developed in the past few years for premium hearing aids, data logging helps determine the length of time the patient has worn his or hear hearing aid and which programs were used the most. This is helpful in determining how a patient is actually using his or her hearing aid, and helps us to make adjustments in the volume within each program that can be used to reset the default.