The two types of hearing aids are the analog and the digital type. They are designed in a manner such that they increase the loudness of the sounds reaching the eardrum, enabling hearing impaired people to understand sounds better. Basically, they fill the gap created by hearing loss.
A hearing aid is made up of 3 main components:
- A microphone that gathers the sound waves in the air and converts them from sound energy to electrical impulses.
- An amplifier which increases the strength of the electrical signal.
- A receiver that will convert the electrical impulse back into sound energy.
The two types of hearing aid available are analog and digital. Both look similar and come in different sizes and styles. The difference between them is in the way they process sound and the individual benefits that they offer.
Analog hearing aids use conventional electronics and amplify the continuous sound waves by simply making them larger. As these instruments cannot differentiate sounds, they amplify all sounds equally. This results in some sounds being too loud while others may be difficult to hear. This can be corrected to a small extent by adjusting the volume of the instrument. An advanced version is now available, and is known as the programmable analog hearing aid. These instruments are equipped with different programs that are saved in it. These programs can be switched on and off depending on the environment.
The other type of hearing aid is the digital hearing aid. These instruments take the incoming signals from the microphone, convert them into a digital format, and then process the signals using digital technology, before converting them back into an analog sound than can be delivered back to the ear. Digital signal processing allows computer programs known as algorithms to be written, that can be customized to each individual’s hearing loss. The sophisticated versions of digital hearing aids are capable of amplifying the softest sounds of speech, while at the same time subtracting out certain types of unwanted noise and avoiding distortion. Further, some varieties also provide the feature of automatic volume control.
Some of the factors to think about when selecting a digital hearing aid is:
- Number of channels or bands that it provides.
- Number of multiple memories that the instrument can support.
- The directional microphone that the instrument supports.
Expansion is another advantage offered by digital hearing aids. Expansion is the name given to process of reducing gain for very soft inputs, so that is it reduces the background noise; for example, the hum of an air conditioner. Expansion cannot be provided in analog devices, as the circuitry required is very complex.
Telecoils are special options available on some models. A telecoil helps the person using the device to listen over the phone more easily. It can also be used with additional listening devices like amplified telephones or amplified television listeners.
Channels are frequency ranges in which the compressive settings can be adjusted individually. Digital hearing devices provide multiple channels that can be used as per the environment that one is in.
Now that we have discussed the advantages of digital hearing aids, let us talk about the major disadvantages. As they focus more on clarity than loudness, it is not suitable for people with profound hearing loss. This is because the circuitry used by digital aids do not provide as high as amplification as the analogous versions can. The other advantage that the analog types have over the digital ones is the cost factor. While analog devices cost about $3,000, the digital ones cost about $5,600. The high costs are attributed to the fact that manufactures have to put in a large amount of resources into research and development.
No doubt, digital hearing aids are far better than the analog programmable one. This is certified by the fact that today, over 75% of all hearing aids sold are digital. Considering all the factors while choosing one is very important. The best hearing aid for you is one that can meet all your needs, offer a good warranty and service.