The great German composer Beethoven wrote his last works while being deaf. How did he do it?

He took a stick in his teeth, pressed it tightly to the piano and heard the music that was playing. In this case, sound vibrations were transmitted not through the outer ear, but through the oral cavity, the Eustachian tube and directly into the middle ear cavity, and then into the inner ear.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.