I recently found this from Wikipedia:
The cause of Beethoven's deafness is unknown, but it has variously been attributed to typhus, auto-immune disorders (such as systemic lupus erythematosus), and even his habit of immersing his head in cold water to stay awake. The explanation from Beethoven's autopsy was that he had a "distended inner ear", which developed lesions over time.
As someone who indulges in cold showers myself on a regular basis, I was slightly taken aback by the possibility that his loss of hearing may have been induced by 'his habit of immersing his head in cold water to stay awake' - could this really be a cause of loss of hearing? If so, how does that work exactly?