A digital hearing aid (DHA) is a compact sound-amplifying device designed to aid people who have a hearing impairment. Like analogue hearing aids, DHA has a microphone that picks up sounds and convert them into digital form, a microprocessor that amplifies and processes the digital signal, a miniature loudspeaker that delivers the sound directly into the ear canal and a battery. All components are contained in a plastic case.

Difference Between Digital And Analog Hearing Aids

Analogue hearing aids amplify (makes louder) all the sounds picked up by the microphone. For example, speech and ambient noise will be amplified together. On the other hand, DHA processes the sound using digital technology. Before transmitting the sound to the speaker, the DHA microprocessor processes the digital signal received by the microphone according to the complex mathematical algorithm. This allows amplifying the sounds of certain frequency according to the individual user settings (personal audiogram), and automatically adjusting the work of DHA to various environments (noisy streets, quiet room, concert hall, etc.).

For users with varying degrees of hearing loss it is difficult to perceive the entire frequency range of external sounds. DHA with multi-channel digital processing allows you to "compose" the output sound by fitting a whole spectrum of the input signal into it. This gives the users with limited hearing abilities the opportunity to perceive the whole range of ambient sounds, despite the personal difficulties of perception of certain frequencies. Moreover, even in this "narrow" range the DHA microprocessor is able to emphasize the desired sounds (e.g. speech), weakening the unwanted loud, high etc. sounds at the same time.

Advantages

According to researches digital hearing aid have a number of significant advantages (compared to analogue hearing aids):

• Digital signal processing helps to reduce noise and distinguish the speech signal from the overall spectrum of sounds which facilitates speech perception.
• Reducing of background noise level increases the user’s comfort (especially in noisy environments, e.g. on the street).
• Setting flexibility provides selective amplification of certain frequencies (in accordance with the personal characteristics of the hearing impaired).
• Effective acoustic feedback reduction.
• Possibility to use directional microphones, which greatly facilitates the perception of sound in certain environments, e.g., when talking face to face, or listening to the remote lecturer.
• Extended frequency range (the ability to hear a large range of sounds).
• “Self-learning" adaptive adjustment which facilitates usage of the device for a number of users. possibility of connecting devices (phones, smartphones, etc.).
• In general, the maximum purification of the sound transmitted to user.