Thanks for your anecdotes and related thoughts. I agree completely that inflammation can impact hearing, and that there is plenty of evidence to support the assertion.
Of related note, sinuses are located close to the ear canals, and when they are congested, let alone stuffed/blocked, it can definitely impact hearing. With regard to diet, dairy products can contribute to congestion and nasal inflammation, so something as simple as avoiding such products on days of listening sessions can make a difference.
I'd even take this line of reasoning to an extreme degree, based on my anecdotal experiences. I have been fasting on occasion for decades, and there is no doubt whatsoever that, broadly speaking, inflammation is decreased as a result. My listening sessions during a fast are typically outstanding, and I believe that the reduction of inflammation is the cause.