Voice

There is a difference in voice in America.  Or perhaps it is because I'm able to understand the words.  In Japan there seems to be more silence, and sound seems much quieter.  In my Japan, there is no sarcasm or impatience.  I don't know if these things are true; it may only be my experience.  Where does a voice exist?  Is it internal or external?  How much control does one have in the voice one hears, in the voice that one speaks?