Also, and completely tangential to the point, I want to mention that Korean mobile-phone &#x2F; meeting etiquette is very interesting.  You don&#x27;t leave the room to take a call.  Instead, you turn toward the wall, lean over, say &quot;yo bo sae o&quot;, and then hold a conversation that is audible to the rest of the room only as a series of quiet murmurs.  I think Korean phonemes are somehow optimal for very quiet conversations like this.  Maybe because there aren&#x27;t very many, and they&#x27;re pretty distinct from each other.  I have no science to back that up.