Although never confirmed, most say that Beethoven's deafness was the result of childhood abuse—his father, opposed to his interest in music, violently boxed his ears. Here's some unconfirmed details on Beethoven's management of his hearing condition (from a Yahoo.answer http://answers.yahoo.com/question/index?qid=20071021190902AAXEyh7):
Around 1796, Beethoven began to lose his hearing.[7] He suffered a severe form of tinnitus, a "ringing" in his ears that made it hard for him to perceive and appreciate music; he would also avoid conversation. He left Vienna for a time for the small Austrian town of Heiligenstadt, where he wrote his Heiligenstadt Testament. He resolved to continue living for and through his art. Over time, his hearing loss became profound: there is a well-attested story that, at the end of the premiere of his Ninth Symphony, he had to be turned around to see the tumultuous applause of the audience; hearing nothing, he began to weep.[8] Beethoven's hearing loss did not affect his ability to compose music, but it made concerts — lucrative sources of income — increasingly difficult.
As an interesting side note, he used a special rod attached to the soundboard on a piano that he could bite, the vibrations would then transfer from the piano to his jaw to increase his perception of sound. A large collection of his hearing aids such as special ear horns can be viewed at the Beethoven House Museum in Bonn, Germany. By 1814 Beethoven was totally deaf, and when visitors saw him play a loud arpeggio or thundering bass notes at his piano remarking, "Ist es nicht schön?" (Isn't that beautiful?), they felt deep sympathy, and saw his courage and sense of humor.[9]
As a result of Beethoven's hearing loss, a unique historical record has been preserved: he kept conversation books (his friends would write in the book so that he could know what they were saying, and he would respond either verbally or in the book) discussing music and other issues, and giving an insight into his thoughts. Even today, the conversation books form the basis for investigation into how he felt his music should be performed and his relationship to art. Some of the books, however, were altered or destroyed by Anton Schindler.[10]
from "A Note on the Text and the Translation" in Andrey Bely, The Silver Dove, trans. John Elsworth (Northwestern UP, 2000), 27: "[The translator is explaining how Bely uses rhythm in new ways in his work.] On occasion the acoustic aspect can be rescued. The Russian for 'ripple' is ryab', which is related to an adjective used recurrently — as a leitmotif — to describe the 'pock-marked peasant woman', Matryona — ryabaya baba. In the first chapter the hero's spiritual confusion is expressed in the image of a blurred reflection on the survace of the pond, where the ripples are likened to 'silver doves', obscuring the depths: golub' [dove] has a distorting effect upon glubina [depth]. The ripples are related to Matryona only on the acoustic level. If the ripples are said to 'pucker' the water-surface, then an acoustic affinity with 'pock-marked' is recreated."
and, continuing, now on the topic of what "pock-marked" really is: "The word ryabaya generates problems of its own. The Russian word has associations which do not naturally attach to any of the equivalents that could be chose in English. [Besides "pock-marked" resulting from smallpox] But the Russian adjective may signify quite a different kind of blemish and moreover carries other association in addition. The marks may be more like what in English are known as 'strawberry marks', a kind of birthmark not associated specifically with disease, and since those marks are red in colour, there is an association with red hair, which is traditionally linked in Russian to the idea of evil. In fact, if all the descriptions of Matryona are considered, both interpretations are fournd to be confirmed."