How Do You Pronounce Thiel?

According to the dictionary I have here, teal and teel are indeed pronounced the same, "teel" or (IPA) "til".

Yes, a dictionary will give you what is historically the most used pronunciation and/or usage and rate it accordingly with the most used to the least used. Some go even further and state what is the correct pronunciation and what is now accepted. That, and there are only so many ways to define how something is said by way of writing it. But, in speech classes one learns that the human voice is so varied and beautiful and expressive and that there is really only one way, barring geographically induced slang and idioms and therefore dialects, to say something.
Now, that is splitting hairs.

I like to pretend its German and yell it out like "Tile"!

LOL, you dont need an engineer to design a first order crossover.

Hi Mitch - actually, I really don't believe that this is hair splitting at all. Stage actors work very hard on their diction to make such differences, and I am sure that a phonetics expert would sound Thiel, teal, and teel all differently. To start with, those are three different dipthongs.

To change this to a musical example, take articulation (think transients, with respect to audio reproduction). We musicians work countless hours on this and many other technical things that the audience is expected to catch.

I submit that these are exactly the kinds of subtle differences that our high end audiophile systems are supposed to accurately resolve. If you are not listening for these kinds of subtle differences, why exactly do you own a hi-fi system?

Granted, the human voice is capable of even more expression and subtlety than other instruments. One of the recordings I always use when testing equipment is John Gielgud's Ages of Man recording (his one man Shakespeare show).