Hey, we're having a friendly conversation here.

The design of the cup is how the engineers manipulate the high frequencies that our brains and ears use to locate sound sources. Sound waves have only three characteristics: amplitude, which we hear as volume, frequency, which we hear as pitch, and start/stop times, which are easy for any device designed to vibrate 20,000 times per second. Sound has no other characteristics. But our ears and brains interpret sound waves in very complicated ways.

Edit: Just saw your stealth edit. I don't think you raised any new points for discussion with it.