Every person with hearing impairment quite naturally wishes to return to normal life free from any physical or psychological discomfort. Of course even the use of most advanced developments in the sphere of audiology cannot help a person suffering from a hearing impairment completely forget that he is using a hearing aid. However it is quite a feasible task to make the listening experience maximally close to the natural process of communication. The variety of modifications and functional characteristics of the hearing aids available to consumers nowadays allows compensating for hearing loss of almost every type and degree. However, the essential condition for a successful compensation is the correct choice of hearing aid.
Choosing a hearing aid one should take into account the specific character and causes of the impairment, the anatomical peculiarities of the patient’s ear, the condition of his auditory function and of course his personal preferences and financial abilities. At the same time, there exist a number of general requirements that a hearing aid must meet to prove really efficient.
The first and the most important requirement is that the hearing aid must allow its user to communicate to other people as naturally as possible, at a normal rate and without making any special effort. Human speech amplified by the aid must be more understandable than without it. That is possible only if the chosen hearing aid is able to convey the user’s own voice without changes, as well as to keep unchanged the qualitative features of other people’s voices. The latter is especially important for communication with strangers. The reproduction of background sounds must also be accurate, as those sounds provide us with information about the environment, including information about potential danger. Whether these conditions are fulfilled depends first of all on the choice of the hearing aid (it is digital aids that are most successful in coping with these tasks), but the sound quality may also be influenced by the quality of the otoplastics used with it.
For the communication through a hearing aid to be absolutely comfortable, it should be totally free of the so-called feedback effect – a typical whistling sound associated with the transmission of the user’s own voice. This unpleasant effect can be avoided by using digital hearing aids featuring the function of feedback suppression.
The loudness of the signal is also an important parameter influencing the quality of communication through a hearing aid. That is particularly true of compensating hearing impairments of anthropogenic nature. Patients suffering from such impairments usually have difficulty detecting quiet sounds and sounds of high frequencies. That difficulty can be overcome by means of modern programmable multi-channel hearing aids. Such aids are capable of amplifying quiet, hardly discernible sounds and bringing the volume of other sounds down to a comfortable level.
Most hearing-impaired people have problems with communicating in a noisy place. For that reason the ability of the hearing aid to recognize speech sounds and differentiate them from background noise proves to be of great importance to them. The function of speech recognition exists in the digital hearing aids using the two-microphone technology. They single out the useful speech part of the signal and amplify it without muffling the rest of the sounds.
Hearing aids with the function of manual program switching are even more advantaged from the point of view of signal volume. A hearing aid featuring several pre-tuned programs gives its owner, for instance, an opportunity to feel comfortable listening to music of any volume – and the settings used for that task are quite different from those used for speech recognition in noisy surroundings. Having a pre-tuned program for phone talks might also prove very useful.
Many patients, especially the elderly ones, find it troublesome to adjust the volume manually depending on the acoustic environment. In such cases it is preferable to use a hearing aid capable of adjusting to changes in the sound signal. That is a function characteristic of automatic hearing aids. They can adjust the volume and the frequency of sound signal in accordance with the changes in the environment.
For people with bilateral hearing impairment it is also very important that the hearing aid should be able to compensate for the loss of spatial hearing and auditory orientation. Those two functions are closely associated with the ability of binaural perception. With such patients, binaural correction (using two hearing aids) will be the best choice. The best effect is achieved with automatic hearing aids capable of symmetrical adjustment.
Of course, a correctly chosen hearing aid should not only provide appropriate sound quality, but also be comfortable in usage. During the consultation between the patient and the doctor among other aspects it is necessary to find out what manner of wearing the hearing aid and its connection with the ear canal seems to the patient most acceptable. The chosen hearing aid should be as comfortable to wear as possible: it shouldn’t put any pressure on the user’s ear, shouldn’t cause soreness or irritation, shouldn’t fall out etc.
Another feature of the hearing aid that is essential for the user’s comfort is its inconspicuousness. Modern technology allows furnishing even the most tiny in-the-canal hearing aids with all the necessary functions, but it should be noted that such hearing aids can be used not for every type of a hearing loss.
Finally, another very important characteristic feature of any hearing aid is its reliability. For someone who has to wear an aid all the time its good working order is essential for normal life. That’s why, when choosing a hearing aid, one should give preference to a well-recognized producer.