can you prove that the blender noise levels were in a high enough decibel range tp produce hearing damage? did you test them with a noise monitor? did osha get involved? again just curious, as a former health & safety professional it is difficult to prove the connection between one & another without verified data. if there is no testing then there could be also other multiple factors that could cause damage as well. not saying you are lying but have seem this argument in the past...
did you document it right after or during your employment there?