For a large group of deaf people, mastering the linguistic structures of the Polish language and the technique of speaking well and lip-reading as the only means of communication turns out to be impossible in most cases. Deaf children learn Polish in schools. They also learn to speak and read speech from the mouth. They constantly use hearing aids and other devices that allow them to use their remaining hearing aids
It is worth knowing that cases of complete deafness are rare. However, hearing damage at the level of 90-100 decibels, although it allows you to react to louder sounds, completely prevents you from hearing speech, the acoustic band of which is between 30 and 60 decibels, and screaming more forte does not exceed 85 decibels. With a hearing loss of 90-100 decibels, some louder speech sounds can be heard by hearing aids.
This is not enough to understand someone’s speech by listening, but such a background sound can make it easier to read the speech from the mouth. However, despite the long-term, many years of speech therapy exercises aimed at shaping speech and reading it from the mouth, few deaf people overcome the language barrier and actively master the language of sound. Reading from the lips is also an extremely difficult art, and the perception of speech in this way is very tiring to the eye and possible only at very close range.
An effective lip reading, if it is not a supplement to auditory perception, but an exclusive form of perception, is possible only for a few or several minutes, after this period visual fatigue, concentrated on the constantly evolving disposition of the interlocutor’s mouth, prevents effective reception. No wonder then that sign language has become the preferred form of communication for the deaf and, created by themselves, lays the foundation for a strong community bond based on a linguistic community, just as in the case of ethnic minorities. .
The linguistic minority created by deaf people is unusual in that their possibilities of development in the field of sound language are limited, therefore, for many deaf people, only sign language remains the primary means of communicating with the environment.