[blell]

> As an example, I never see Japanese people on their speakerphones in public. Some other cultures seem more likely to view it as acceptable.

Demographics is everything. Import speakerphone users, get speakerphone usage.

[dwd]

Some cultural groups also seem more likely to make video calls, where they are walking and talking to someone on their phone screen.

Still not a reason not to use headphones as all but the cheapest come with a built-in microphone.