[precommunicator]

I've had to answer a urgent phone call on a bus once (on headphones) and I felt bad about that.

I don't understand how can you even think this is ever acceptable.

However, same as the 54% mentioned in the article I won't ask them, but for a different reason: noise canceling headphones means unless someone is playing a concert, it won't bother me.

[RandomBacon]

Phone microphones are generally pretty good. You don't need to shout or even talk loudly into them. Usually talking quieter than a normal conversation will be easily picked up by the phone's microphone.

As long as you talk at an appropriate level, there is no need to feel bad.