|
DIGITAL
HEARING AIDS
Analogue to digital hearing aids - advancements are apparent
A lot of research has happened over the years in the domain of hearing aids. The effort has yielded desired results and thus the latest ones i.e. digital hearing aids are of an enhanced quality than earlier versions.
Hearing loss is not a recently discovered issue and nor are analogue or digital hearing aids freshly invented gadgets. Both the problem and solution have existed for years. However with technological advancements and medical progression, the look and performance of the solution i.e.
hearing aids have undergone radical modifications.
There was a time when sound was amplified with the use of huge ear trumpets. Not very useful the ear trumpets and they were eventually replaced by electrical hearing aids. The initial ones were quite bulky and obviously not as technically sophisticated as to what we have today. Owing to intensive research and advancements in the field, both these drawbacks have been successfully taken care of. The latest hearing aids are the digital hearing aids. At their best they are accurate when it comes to sound quality, are compact, and automated. However before further elaborating upon the digital technique and associated features, it is important to know about the other most popular option, the analogue hearing aids.
The analogue hearing aids catch the sound waves – converts them into electrical signals – sends the converted signals to the amplifier – the amplifier works on the power of the signals, i.e. increases it – and finally the amplified signal is sent to the ear. This mechanism treats all sounds at par i.e. all sounds are amplified equally. So if somebody is talking with you and at the same time the television set is switched on and two or more people are interacting with each other, the analog hearing aids will send all signals at equal power. So you will have all sounds coming in, with equal intensity. However because this is obviously not desired, the user has the option of making adjustments. The user can adjust the sound volume. It can be like setting a different volume for different channels, depending upon the preferences. But then hearing loss is not just volume and such adjustments are not always convenient, so the need mandated further research.
Digital signal processing was thus introduced in 1987. The earliest versions of the digital hearing aids were expensive and bulky and needed more batteries than usual. Cheap hearing aids thus prevailed and the digital substitutes were more or less rejected. But that was not the end of digital technique in hearing aids. The mechanism was reintroduced about a decade later, now with enhanced features and usability. Since then digital hearing aids have grown in popularity.
The digital technology has one major advantage over the analogue variant. The digital hearing aids can distinguish between speech and background noises. Thus the sounds are filtered, to ensure better hearing. The filtering function suppresses the additional sound in a noisy environment. This largely happens because digital hearing aids do not convert signals into electrical signals, but instead change them into numerical codes, before amplifying. This mechanism is more accurate than the one in the case of analogue technique. A sound pitch is clearly identified in this conversion type, which enables specific amplification of all incoming sounds. The digital mechanism itself adjusts to the listener’s environment. Further the chip installed inside digital hearing aids, also makes adjustment as per the user’s hearing loss.
Though digital hearing aids cannot be classified as cheap hearing
aids, in comparison to analogue hearing aids, but they are clearly more useful. So if you are planning to have hearing aid tests done, do ask your
your hearing aid audiologist about the types available and the best for your situation.
Copyright.
Stephen Auker
Talking Web Pages 2009
|
