This would occur to some degree even on my electronics that were running on a DC battery separate from the home's circuit. Less intense fluctuations still showed up in spectrograms when recording music.

But can they notice the difference on a random track, not on special test audio? Probably not.

> Just play some music on your laptop/phone speakers and move the device around a bit, and you'll hear striking differences in highs and lows.

My laptop has speakers directed downwards, so putting a palm under it (to reflect sound upwards) increases the quality.

This is why mix engineers have multiple sets of speakers, so they can periodically reset their perception. Additionally, it is well documented that the top scoring speakers on Audio Science Review (where people who think linear reproduction of audio is the only job of a speaker) do not align well with the top tool choices for audio professionals, and this is not because they are governed by supersition.

There is not currently a metric for many of the things that become essential as soon as you start listening critically and having to make binding decisions from your perception - will it fatigue me, is the speaker lying to me, dimensionality, etc. Saying these are problems with your listening environment is punting on the problem of the actual duty a speaker is required to fulfil.

I don't see why an audiophile, who is a critical listener, should be any different. They're obviously doing it without a generated artefact from their listening, so there's no data based feedback loop for the quality of their experience, but it's a hobby, so everyone's preferences have value.