[0] https://www.bose.com/en_us/products/wellness/conversation_en...
[0] https://www.bose.com/en_us/products/wellness/conversation_en...
[0] http://www.washingtonpost.com/wp-dyn/content/article/2008/04...
You are hitting your nail straight on the head, my friend.
Main culprit is: Unfinished ceiling/metallic ceilings (usually corrugated steel pannels, either square or triangular profile pattern).
It's very trendy now to have exposed mechanical equipment and venting, people do not bat an eye anymore. Been ok for about 25 years now. Source: me, working in the business, I specifically avoid any public place with such unfinished ceilings. I cannot stand it anymore!
My only criticism is that they use HSP during phone calls, then switch back to A2DP when music/audio resumes. This means that audio quality during phone calls is significantly worse than normal audio output, but this occurs with every bluetooth headset I have tried.
E.g. in Android, I think Oreo finally added some HFP 1.6 support, and 16kz SCO output should be theoretically possible (I wasn't able to get it to work). But for some reason, 8khz SCO input remains explicitly unsupported, as per the AudioManager doc:
> "The following restrictions apply on [SCO] input streams: [...] the sampling must be 8kHz"
From what I've seen, most bluetooth devices and cellular providers don't seem to support 16khz speech either. At this rate, it seems like most of us won't enjoy wide band bluetooth calls until 2030 or so.