The reasons why we feel uncomfortable against voice by cell phone in commuter trains are the followings.

(1)Human can ignore everything that we can estimate easily,

(2)However, the one-side cell phone voice gives us heavy load in our brain in order to reconstruct the whole communication unconsciously.

(3)So we feel tension strongly against one-side voice.

Additionally,

(4) Pretending muffled voice

is not effective. Because our palm has no function to sponge aerial vibration of voice frequent band.

That is just a play to excuse them (and poor performance despairingly)

I think

"Speak proudly in the eyes of angry persons"

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I am afraid that train companies must be hard to call repeatedly to "please refrain".

The work seems to be stressful though they are not illegal acts.(But what the company does is just calling?)

On the other hand, I think that subways are easier than usual train. They feel free to care such cell phone problems.

However, subways also become to supply the cell phone service recently.

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At first, I wonder what they are thinking, but this reason is simple.

Though kinds and amounts of contents increase, time for human is not unchanged. For the cell phone carrier and contents provider companies, "time of commute" is a battle field.

The subway companies also might be afraid that some persons avoid using the subway because of NA (not available) of the internet services.

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After all, it is cheaper for everyone that the management that allows customers to use mail, twitter, Facebook and Line, and calls repeatedly ""please refrain".