There's a potential systemic bias involved in this that the report does not consider (unsurprisingly). What if the particular firmware caused hearing damage tha

There's a potential systemic bias involved in this that the report does not consider (unsurprisingly). What if the particular firmware caused hearing damage that now causes these users to think the noise-cancelling performance has deteriorated? I have no reason to think this is the case, but wow, what a confounder to have to deal with!