The 'ayin and the het. This is a case where there really is no dispute how it is supposed to be said. Ask an Israeli about it and he'll say something like, "The Yemenites have the correct Hebrew; they say the hhhhhet and the 'aaaaayin." He will emphasize those two letters, showing that, with some effort, he can actually pronounce them. And yet, in day to day life, he will NOT pronounce them properly. I conclude that this is a combination of laziness and a fear of being laughed at. What really irks me is that the younger Israelis whose grandparents came from Yemen or Morocco or Iraq or Syria etc. will also refuse to pronounce these two letters properly. Are they ashamed of their own heritage? One can here the het being pronounced clearly on Israeli radio but the 'ayin is more rare. I learned how to say it be exposing myself to Arabic being spoken (this was before I went to Israel and there was an Arabic radio station in my area). When I did arrive in Israel, I spoke Hebrew as properly as I knew at the time and this included the correct pronunciation of the 'ayin and the het. People knew I was American - and I got nothing but admiration for my efforts - but this was a long time ago. Maybe things have changed for the worse. In any case, it has been said that it is virtually impossible for a Westerner to master the pronunciation of these two letters. That one must be raised with it. I am living proof that this is not so and I've met others (very few) who have also learned. I am not going to try to describe their pronunciation in print; you just need to hear them. They are, of course, both guttural. Here's a good article about it:
http://en.wikipedia.org/wiki/AyinHere are some tidbits about the 'ayin and het:
Talmud Meghilla (24 and Yerushlami Berakhoth 82). "Those who read the 'ayin like aleph are not to publicly read from the Torah and are not to participate in the blessing of the Cohanim".
I shall quote from my mentor, Ben Siyyon Cohen "If, until now they had an excuse to say 'it wasn't our fault for we didn't know the pronunciation of the het and 'ayin and we had nobody from whom to learn'. Behold, now in the Land of Israel they have the ability and opportunity to learn and yet they make no effort to do so or to teach them to their children. Those people will be judged as though they sinned on purpose. For how can a religious Jew entertain the concept of reading prayers and Torah while substituting the aleph for the 'ayin?. How will he read "wa'avadhtem ("you shall serve" but, with an aleph, it would mean "you shall destroy") G-d". "Nishba' haShem ("you will swear to G-d" but, with an aleph, it would mean "G-d will be taken captive")". "Laahava eth hashem ul'ovdo ("to love G-d and to serve Him" but, with an aleph, it would mean "to love G-d and to lose Him")". And similar to these? Is this not blasphemy and cursing heavenward if he is able to learn to pronounce the 'ayin and yet he is too lazy, or for whatever reason, neglects doing so? How much more so those who err and misinterpret "Do not forsake the teachings of your mother..." as if they were commanded to pursue traditions even after it becomes clear that they are corrupt... How much more so if he is in the Land of Israel, that if he wishes to learn, he can learn the correct pronunciation of the letters easily and yet he makes no effort. He will be judged as "mezid" (sinning on purpose) and as one who makes light (of the commandments)..."
Regarding the heth. It is counted amongst the guttural letters whereas the khaf has its source in the back of the pallet. This, alone should make it clear they cannot have the same sound. The sound of the heth is close to that of the he and, in some places, they were pronounced the same. We find in Meghilla (24:b) "concerning Rav Hiyya, who used to pronounce the heth like a he, Rabbenu haQqadosh told him 'when you reach to word "wehhikiti lahaShem", do you not find yourself blaspheming? (with a heth, it means, "I waited for G-d" but with a he, it means "I struck G-d")"
We find that Ashkenazi Jews used to pronounce the heth the same as the he as well. These are the words of R. Yosef Ometz (Germany, letter 21):
"And so the reading of the heth, which we Ashkenazim pronounce like the he, it seems to me that we are correct." And he brings three pieces of evidence against the habit of Polish Jews - who would pronounce it like the soft khaf.
Also we find R. Shemuel haLlewi (lived in Piorda, Germany about 300 years ago), in his book "Nahalath Shiv'ah" (chapter 46) on the letter heth, regarding the spelling of the name "Hanokh". He writes, as a matter of fact, that the Ashkenazim pronounce the heth like the he and these are his words "in any case, it is known that the Ashkenazim pronounce the heth like the he".
Nevertheless, it is obvious that the heth is not the same as the he. However, it behaves much like the he in Hebrew grammer. Had the heth been originally pronounced like the khaf, we would have a hard time explaining how ancient sages and Jews in Germany came to pronounce it like a he; after all, they had no problems pronouncing the khaf. Why would they have changed the heth to a he?
What I quoted above regarding the 'ayin, and how today's Jews have an obligation to learn the correct way of reading it, applies equally to the het. There is no excuse for not learning it correctly.