I leave church some times with my ears ringing.
Be
very careful with your ears. Otherwise, it may well occur
one day that the ringing no longer stops, and
stays with you for the rest of your life !
This phenomenon is known as
tinnitus. Although it may have several different origins, the most frequent one today is over-exposure to excessive sound/noise. Many people get it from discotheques or rock concerts, or even from excessive use of headphones (especially those small earphones that come with mp3 players), but even classical musicians must be careful about this.
I don't wish to frighten you, but just to invite you to be careful. I know that with a beautiful organ, it is easy to get carried away and go on and on and on, but you should really avoid playing with too many loud stops for too much time. Play softly as much as you can, to "rest" your ears between loud passages. And if they nevertheless begin to ring,
stop playing. In that case, don't just wait until the ringing goes away until playing again, but do something else for a day or two before going back to the organ. It is also wise to consult a doctor as soon as possible if the ringing does not stop after 24 hours.
(Disclaimer: I am not a medical doctor, and the above should therefore
not be considered as professional medical advice.)