Very superficial

Layman John was visiting Kyoto. His host, a professor from the biology conference he was attending, took him to meet an English speaking master living in one of the compounds of Daitokoji temple. The weather was terrible, downpours of rain, lightning  and thunder. They sat in a room where a skylight let in the rains that rustled away down some guttering. Layman John was introduced in a flamboyant manner as if he were a Western expert in Zen. He feared the worst. The master smiled in a polite greeting. Just then there was an enormous flash and a roar of thunder. The Master leant forward and said “Doctor John–Tell me - where does the thunder sound?” Layman John hesitated and then muttered something about it being both in the sky and in the head. “Very superficial, Doctor John, very superficial.” commented the Master.


Well then- where does the thunder sound?