There are two types of technology used to process sound, one is analogue and the other digital, but analogue technology is gradually being phased out in favour of digital. This is the same principal of sound technology within a television set, analogue televisions are being phased out for digital televisions. However the body worn hearing aids are still analogue as well as some bone conduction hearing aids. Digital is in theory a newer and better technology and in many ways it is superior, but in some cases an analogue hearing aid can be best. You would be advised to be guided by your audiologist as to your requirements. At the same time a digital hearing aid is not a ploy to get more money out of a purchaser, it is a process which can reduce some of the worse aspects of hearing aids and makes a radical improvement. It is fair to say that an analogue hearing aid has not got the bells and whistles of a digital system and it cannot be tweaked as much, but for some it is a necessity, it depends on your type of deafness.
Analogue hearing aids.
An analogue hearing aid converts sounds into an electric current, which is then modified in an amplifier and reconverted into sound by a receiver. This final amplification of all sound is passed into the ear and is heard by the patient.
Sensorineural deafness normally means that your ear is no longer capable of being sensitive to sound, so the amplifier is the crucial part of the hearing aid. In simple scientific terms the amplifier uses the battery to increase the voltage of the signal coming from the microphone. In any circuitry system, this will increase the volume of the final sound. Once the sound has been amplified it is then sent to the loudspeaker, which is attached by a tube that is fixed into the earpiece, which is then inserted into the ear canal.
A disadvantage of this type of hearing aid is that it amplifies all sound equally, that means that it amplifies the sounds that you do not wish to hear, such as background noise as much as it amplifies sound that you wish to focus on. Also if the sound coming in is distorted, then the distortion is also amplified along with the incoming sound.
However there are many people who would not change an analogue hearing aid because for some it can have advantages. It uses a refined transistor and this means that the sound can be sorted into bands, which gives the user a degree of control over low, middle and high-pitched sounds. Not only is it cheaper than a digital hearing aid and it is far tougher, and it does not contain small computer electronics that may be temperamental.
Analogue hearing aids contain basic technology they do not have the precision or the flexibility of digital, but the modern ones contain programmable models, which achieve good sound quality. They will eventually all be replaced by digital, but at the moment there is a choice.
The digital hearing aid
The theory is the same as with analogue aids, the sound is collected by the microphone, but before it is sent to the amplifier it is processed. That means that it is sent to a microscopic computer, which edits the sound; it removes any extraneous sounds such as the wind, interference, or muffled talking. It then sends the “purified” sound to the amplifier as an analogue signal. It continues to work in exactly the same way as an analogue hearing aid.
Some people have reported the fact that they find the adjustment to digital from analogue difficult, but that has nothing to do with the technology, it is more about resistance to change. Those patients that start with a digital hearing aid report that in comparison the sound from an analogue hearing aid is very raw.
The digital hearing aid uses a microchip to turn all the sound into a binary code of zeros and ones (0 + 1). After the sound has been digitalized they can then be separated into bands, which are individually adjusted to suit the patient’s unique needs, which are then programmed into the microchip.
There are many advantages not least of which is they are capable of changing the sound levels to adjust them to a changing situation. For instance if you are sitting in a café and talking to a friend, and a train goes by the hearing aid can adjust the level of your friends voice, thus making the voice more audible. They can work on up to twenty bands of sound at once and they make millions of calculations every single second. Because it has so many bands it can manipulate background noise and minimize it so that it is where it should be in the background and not interfering with your hearing. They deal with everyday situations and can help a person to hear over the telephone, because they process sound up to ninety percent faster than the older analogue technology.
The bottom line is that if your hearing problems are in your middle ear and you do not need a bone conduction hearing aid then it will be better for you. Few people if you ask your friends and family have started with a digital hearing aid and then switched to analogue.