Determine the type of device that can be digital or analog. The latter amplify all sound signals equally, and when wearing them, the user is better at hearing not only sounds not available to him before, but also sounds that were heard perfectly normally before. Now those sounds are getting too loud. With this amplification, the brain and ear get an extra noise load, the intelligibility of speech is lost, as a result the user experiences irritation and loses the desire to use such devices for a long time. The main plus of such device is low cost.
The main difference between digital devices is that they selectively amplify sounds only at frequencies in which hearing decline occurs. This device can be adjusted for individual hearing loss. At the same time, the more audiogram points in the device, the more accurate the settings can be.
In a digital hearing aid, sound processes a computer that separates speech from noise, amplifying speech range sounds and weakening noises of noise. So speech becomes more legible, and the brain gets rid of excessive load. People suffering from hypertension and frequent headaches are advised to use devices with enhanced noise suppression.
Sound is processed in multiple bands, individually in each. And the more audio processing strips, the more clean it gets at the output.
Hearing aids are equipped with microphones operating in two modes — omnidirectional and directional. In the first case, you will hear everyone around, in the second — that interlocutor who will be right in front of you. For children and people often in large classrooms, devices with omnidirectional microphone will be suitable.
Each unit has a set of programs. When selecting them, you should focus on the environment in which the device will be used most often. In the most modern models, these programs can automatically switch when the user changes noise conditions.