Notebooks which Beethoven used from 1818 onwards to communicate with his visitors once his hearing began to decline. The visitor wrote down a question, to which Beethoven generally responded verbally.Following Beethovens death, his secretary Anton Schindler appropriated the books and misused them by falsifying or removing entries. In so doing he not only wanted to make his own role in Beethovens life seem more important but also to throw a more glorious light on the composers life. The exact number of conversation books used by Beethoven and later appropriated by Schindler is unknown. The Beethoven biographer Thayer mentions around 400. This number might, however, be founded on a misunderstanding. In 1846 Schinder sold all of the conversation books in his possession to the Berlin Royal Library, now the Berlin State Library - Prussian Cultural Heritage. They numbered 137 and several loose sheets.