• Advanced Signal Processing - Advanced signal processing automatically adjusts the amount of amplification (gain) the hearing instrument provides according to the loudness of the sound reaching its microphone. In this way, softer sounds are amplified more than louder sounds. Traditional linear hearing instrument circuits provide a set amount of gain regardless of the loudness of the sound reaching the microphone. Linear amplification can result in softer sounds remaining too soft and louder sounds being uncomfortably loud.

A major component of most advanced signal processing is compression. That is, the hearing instrument circuit constantly adjusts the amount of gain available so that softer sounds can be more easily heard, while avoiding discomfort from louder sounds. Different signal processing configurations can vary the amount of compression, as well as the loudness level at which compression is activated. Digital hearing instruments have several signal processing options to choose from based on the user's preferences and needs. This can benefit hearing-instrument users in noisy situations as well as users who experience loudness discomfort at softer-than-normal levels, known as recruitment.

• Multi-Channel Capability - The amount of gain a hearing instrument provides at each pitch or frequency is called its frequency response. Digital hearing instruments divide the frequency response into two or more channels of control. Each channel can be adjusted independently so that different advanced signal processing schemes can be applied to each frequency region. This allows the hearing instrument to respond differently for low-pitched sounds than for high-pitched sounds, better accommodating a hearing-instrument user with recruitment. Because recruitment may be present only at some pitches, multi-channel capability provides more flexibility to meet this need.

• Multi-Memory Capability - Many digital hearing instruments have memory, allowing them to store more than one frequency response or program. Multiple memories allow the user to choose from different frequency responses and signal processing options with a remote control, by pressing a button on the hearing instrument or the hearing aid may have the ability to switch automatically. Multiple memories are useful for those who communicate in many different listening situations or have fluctuating hearing loss. The audiologist and the hearing instrument wearer together decide which hearing instrument responses to store in memory. The programs chosen are based on the wearer's most frequent and demanding listening situations (for example, attending meetings, listening to music or going to a restaurant).

• Multi-Microphone Capability - Some digital hearing instruments have separate microphone settings that allow the user to pick up sound either from a broad area (omnidirectional) or from a narrower listening range (directional microphone). This is similar to a camera having a wide angle and zoom lens. In noisy listening situations, the directional microphone can suppress sounds that come from behind (usually competing noise), improving the hearing-instrument user's ability to hear speech that comes from the front. The hearing-instrument user can choose between microphone settings as listening situations vary. Some instruments will automatically switch between microphone modes depending on the listening environment.

• Noise Reduction Capability - Some digital instruments are designed to identify noise and automatically reduce the amplification in the frequency regions where it is detected. This may provide the user with increased ease of listening in background noise.

Additional Benefits

No hearing instrument can eliminate background noise, especially when the "noise" is competing speech. However, digital hearing instruments with multiple channels, multiple microphones, and advanced signal processing have been shown to improve speech understanding and ease of listening for many users.

Remote controls may be helpful for those who have difficulty manipulating small hearing instrument controls. In addition, some remote controls can be operated from a pocket or purse, allowing less obvious hearing instrument adjustment.

If hearing changes, digital hearing instruments can be reprogrammed, avoiding hearing instrument replacement costs. Current digital hearing instruments are appropriate for mild to severe hearing losses.

Costs for Digital Hearing Instruments

Digital hearing instruments sometimes can cost twice as much as traditional hearing instruments. The cost of advanced technology instruments depends on the hearing instrument style, as well as the type of technology options chosen.

Obtaining Digital Hearing Instruments

Before obtaining hearing instruments, an examination by an ear specialist is recommended. Then, an evaluation of hearing and listening needs will be completed. Based on evaluation results, the advantages and limitations of traditional and advanced technology hearing instruments will be discussed. The hearing-instrument wearer chooses the style and special features that best suit his or her needs.

A demonstration of digital and traditional hearing instruments is available at Boys Town National Research Hospital, on referral from an audiologist.

Once a decision has been made, the audiologist orders the digital hearing instruments. The audiologist fits the hearing instruments and adjusts them to the wearer's needs. An orientation to the care, use and maintenance of the hearing instruments will be completed. Follow-up appointments will be scheduled as needed to ensure that the wearer receives the most benefit possible from their hearing instruments.

Hearing instruments are available for a 30-day trial. If they are returned within the trial period, the cost of the hearing instruments is refundable, less a non-refundable fitting and restocking fee.

Boys Town National Research Hospital does not endorse specific products or manufacturers. Contact a local certified audiologist or your state's speech and hearing association for services and products available in your area.