Reinventing sound – Analogue Vs Digital hearing aids
Hearing aids have been conventionally built from analogue circuits till date, and digital circuits are a superior and a new venture into the hearing aids market. A hearing aid is designed and tested such that it produces the required amount of amplification of existing sound such that a person hard of hearing will be able to make out the speech and noises around him clearly. Analogue and digital converters do the same job but slightly differently. Any hearing aid has the three components which are a microphone to capture the sound, an amplifier to increase the volume of the sound, and a receiver to receive the signals from the amplifier and transmits it to the ear.
An analogue circuit receives this sound signal from the microphone as continuously varying electric signals and feeds them to the amplifier which increases the sound according to requirements. It follows a method called automatic gain control by which it amplifies only quiet sounds but does not amplify already loud sounds so that the speaker does not face discomfort. Digital circuitry is a new technology to be used in the hearing aids. Here the microphone sends signals in the form of bits of data which is again converted into numbers which can be operated on an inbuilt chip and hence it is easy to manipulate the sound in almost any way.
Digital circuitry is much better in operation with higher quality sounds and more accuracy than any other thing in the market and hence it is costlier than analogue. Due to the amplification of the entire sound in analogue circuitry people who use it mostly complain about not able to hear anything due to the loud noise it generates. Digital circuitry has a solution for this problem where we can reduce the background noise appreciably enough to hear the person clearly and hence can distinguish between sound and speech 
efficiently. Digital circuits, unlike analogue, also safeguard the existing hearing level of the people without damaging the ears even more and has additional features to offer at the cost of extra money, and it can be noted that it is worth the extra buck. All said and done when compared to digital, analogue happens to be more robust, costing lesser than digital and hence it still has a strong foothold in the hearing aid market.
There are various hearing aid brands out there, one very reliable name is the Bernafon hearing aids brand.