Here's what David writes:
"Thank you for your excellent videos and emails - they have really helped me improve my playing and given me more confidence.
I practice on the organ as often as I can, but unfortunately that is not every day as I work full time and the church building is often in use in the evenings for other things, so even if there is access to the organ, I cannot play it or there would be complaints about the sound!
I regularly play for Sunday services, weddings and funerals. Since I have subscribed to your emails and watched your videos, I have had many more compliments than I did before.
Thanks again for sharing your wisdom and experience."
I can't say that it's a worse practice without the sound. No, simply you have to get used to listen with your mind. That's why ear training comes in handy too for organists.