Capitol Ear Nose and Throat Clinic

HEARING AID TECHNOLOGY

What are the 3 types of technology available in hearing aids?

  • Linear:
    Linear hearing aids use analog circuitry and are the "most basic" hearing aids available. They are made at the manufacturing lab and also programmed there based on your hearing test. They amplify soft, average and loud sounds equally and are usually the least expensive to purchase.

  • Analog/Programmable: rogrammable hearing aids are made at the manufacturing lab and are digitally programmed by the Audiologist in the office using specific software.  These hearing aids typically amplify the soft sounds and decrease the volume of the louder sounds in the environment.  Some have multiple memories for improved understanding in various environments.
  • Digital
    Digital hearing aids are the latest and most advanced technology available.  They are also made at the manufacturing lab and programmed by the Audiologist in the office using special software.  Digital Signal Processing (DSP) (described below) is used in these hearing aids.   These hearing aids have multiple memories and the option of Directional Microphones (described below) to help improve speech in noise.   They can be adjusted to automatically eliminate feedback in certain situations.   They are most flexible for adjustments and are the most expensive and advanced hearing aid technology available.

    Even the smallest completely-in-the-canal hearing aids are now available in digital versions, with as much programming sophistication.

What else is special about programmable hearing aids?

Because of the numerous controls that are available through programming software, hearing aid manufacturers have been able to incorporate significantly advanced technology in programmable hearing devices.   Some of these innovations are listed below

  • Multiple Programs
    Two to four separate programs that are appropriate for different listening situations can be loaded into the device. For instance, the user can use one program for listening in quiet, another program for listening in a background of noise, and a third program for speaking on the telephone. Switching from program to program can be done by means of a remote control or with a toggle switch or push button on the instrument.
  • Wide Dynamic Range Compression
    A major problem for people with sensorineural hearing loss is discomfort as a result of changes in sound intensity. Typically, patients' tolerance for low-frequency sounds is different than their tolerance for high-frequency sounds.   By accounting for these differences, programmable hearing aids can be set so that low-intensity sounds will remain audible, moderate-intensity sounds will be comfortably loud, and high-intensity sounds will be loud but not uncomfortable for all frequencies.
  • Digital Sound Processing
    Completely digital devices provide the greatest degree of programming flexibility and specificity.   Entering sound undergoes analog to digital conversion, is processed within the hearing aid, and then is transformed back into sound by digital to analog conversion. And of course, all of this is done in real time so that the user does not notice a discrepancy between sound perception and the visual aspects of speech. Because of digital capability, several devices with digital signal processing provide the equivalent of a multi-channel graphic level equalizer.
  • Directional Microphones
    By using two separate microphones, one facing toward the front and the other facing toward the back, hearing aids can effectively minimize distracting noise from the back while emphasizing the desired signal from the front.   This has been one of the most substantial advances in hearing aid technology, because it directly addresses a common and difficult complaint of patients with sensorineural hearing loss: listening in a background of noise.

Who is a candidate for a programmable hearing aid?

Anyone who is a candidate for a hearing aid is a candidate for a programmable or digital hearing aid.

Website links for hearing aid manufacturers