Digital appears to be a term everyone is using these days to describe new technology in products such as cameras, DVD’s, and television sets. It also applies to many new products in healthcare including hearing aids.

When talking about digital technology, we mean that information is broken in to a computer code which can then be manipulated or altered using that computer code. For example, a digital camera records the image it takes when the shutter is opened and converts it into a computer code. The image can then be enlarged or reduced. The contrast can be increased or changes can be made to shading and color to improve the image and make it clearer.

This same technology can be used in hearing aids to capture sound and convert it to a computer code where it can be also be manipulated to make it clearer for the person wearing the hearing aid. The sound collected by the digital hearing aid can be manipulated in ways that are not possible with traditional analog hearing aids resulting in a variety of benefits to the hearing aid user:

Individual tuning or programmability - when converting sound into computer code, the computer chip inside the digital hearing aid can break the sound up into different bands across a broad range of frequencies (or pitch) from high to low. These bands can then be programmed separately to increase the volume of sounds in the ranges needed to more perfectly match an individuals hearing loss. This program can also be changed over the lifespan of the hearing aid as the wearer’s hearing loss changes or their listening needs change.

Noise reduction - many digital hearing aids can reduce the amount of background noise you hear. While the computer chip in the digital hearing aid converts the sound into a computer code, it can analyze the sound to determine if it contains modulations such as speech or if it contains noise. If it is determines the sound to be noise, it reduces the volume of that sound in just the frequency band where the noise is found while preserving the overall sound quality of speech. Previously, hearing aids would have to reduce overall volume in an attempt to make the hearing aid more comfortable in noise.

Directional microphones - another way digital hearing aids can help reduce background noise is through the use of multiple microphones that are digitally coordinated to reduce the amplification of sounds to the side and rear of the individual wearing the hearing the hearing aid. This allows for the sound in front to be more easily heard in relation to the sounds behind and to the sides of the hearing aid user when in situations where background noise is making it difficult to understand conversation. Some digital hearing aids require the pushing of a button to change the directionality of the microphones while other digital hearing aids automatically change to the directional mode when it is sensed that the user is in an environment with high noise levels.

Feedback cancellation - hearing aid wearers often experience uncomfortable feedback in a wide variety of everyday situations. Feedback is when amplified sound coming out of the hearing aid reaches the hearing aid microphone and is amplified again causing a high pitch whistle. This can happen when putting on a hat or hugging a loved one when something gets close to the ear and forces the amplified sound leaking out of the ear canal back into the hearing aid microphone. This can be especially bothersome with telephone use in some hearing aids. Digital feedback cancellation with the hearing aid constantly monitoring the sound returning to the microphone and using the presentation of an inverted signal to cancel the feedback when it is detected. This prevents the occurrence of feedback without reducing the volume of the hearing aid.

Automatic volume control - most digital hearing aids come without a volume control. Comfortable listening levels are established when the hearing aid is programmed and the hearing aid then adjusts the hearing aid so that soft sounds are audible, speech level sounds are comfortable and loud sounds are loud but tolerable. This happens with the computer chip in the hearing aid processing thousands of sound per second and making decisions on how to amplify these sounds across all the individual frequency bands. This means that when a loud sound enters the hearing aid, only the volume for the frequency region of the noise is reduced and not the overall volume of the hearing aid.

Digital hearing aids come in all sizes and styles and now are available in many models that start at prices nearly as low as what traditional hearing aids have cost in the past. Trial periods with the option to return the hearing aid for a full refund allow both new hearing aid users and users of older hearing aid technology to discover for themselves the benefits of digital hearing aid technology. However, technology is only one part of successful hearing aid use and good hearing. It is also very important that the hearing aid is programmed correctly by an experienced audiologist. The audiologist should be skilled at providing appropriate counseling and be readily available for follow-up appointments to make the adjustments that digital technology allows to meet the individual and unique needs of each hearing aid user.

Would you like to learn more about digital hearing aids? We welcome your questions and invite you to contact us for an appointment to discuss your options. Please call 360.892.3445 or email .

Learn more about the myths and facts about hearing aids and decide which hearing aid is best for you. Read about Jeff Garnett and the services we provide at Evergreen Audiology Clinic.