What is the correct way to pronounce Hashem’s name in Shmoneh Esrei and other brachos?

[Professor L. Levine via Avodah]

 From today's OU Halacha Yomis


Q. What is the correct way to pronounce Hashem's name in Shmoneh Esrei
and other brachos?


A. Rav Shlomo Zalman Ehrenreich, HY"D the Av Bais Din of Shomloy in
Hungary, once wrote a letter on this subject. It reads in part, "We have
a tradition in our hands from Sinai, from the mouth of the Almighty,
that the reading of the honored and awesome name of Hashem is AH -- DOY
-- NOY (AH-DOE -- NOY or AH-DOW-NOY) using the vowelization of Chataf
Patach for the Aleph, a Cholam for the Daled and a Kamatz for the Nun..."

"Our master the Chasam Sofer and the author of the Yesod V'Shoresh
HaAvodah, zt"l and a whole group of Geonim and Kedoshim have already
warned us that unfortunately there are many mistakes concerning this. One
needs to be very careful about this matter for a common mistake has spread
among the masses and even among those with fear of Hashem. Through a lack
of concentration, the Daled (of Hashem's pronounced name) is said with
a Sheva as "AHD-ENOY." It is certain that whoever pronounces Hashem's
name this way has not said Hashem's name at all and must repeat the
bracha again, and so did the Chasam Sofer rule."

Rav Shimon Schwab, zt"l in his classic work on Siddur, Iyun Tefilla
(p. 25), adds that one should also be careful not to say AH -- DEE --
NOY. He writes: "One must pronounce the Daled with a Cholam (DOY, DOE
or DOW) and the Nun with a Kamatz, and not use a Chirik under the Daled
(DEE) as is the custom of some who are mistaken and think that they
are pronouncing the Name properly... This is a disgrace of the honored
and awesome Name. One who pronounces Hashem's name with a Chirik even
a hundred times a day is not transgressing the prohibition of saying
Hashem's name in vain."

Rav Pinchas Scheinberg, zt"l was once asked if Ahd-enoy or Ahdeenoy are
acceptable be'dieved, after the fact. His response was a resounding "No!"