From a linguist's point of view this is a perfect example of the chaos that ensues when people try to say how things are pronounced without describing the speech sounds using standard vocabulary.
Here are the inept pronunciation instructions on the LaTeX project website:
> «Lah-tech» or «Lay-tech» (to rhyme with «blech» or «Bertolt Brecht»)
The pronunciation of the 'ch' in 'blech' isn't really standardized, so that's not much help. If we go by the German pronunciation of Brecht then the sound should be [ç], i.e. a voiceless palatal fricative. But this seems to be a mistake, as Knuth intended the X in TeX to be [x], i.e. a voiceless velar fricative. In German, [ç] is an allophone of /x/ (conditioned by the preceding vowel), but they are distinct sounds, and Knuth's directions for the pronunciation of TeX unambiguously specify [x]. It seems unlikely that this difference between the X in LaTeX and the X in TeX is intentional, so maybe this was a confused attempt to identify the [x] sound.
Really then, it's anyone's guess how LaTeX is supposed to be pronounced, since no-one with authority to specify has bothered to look up the IPA symbols for the relevant speech sounds. But IMO while [leɪtɛk] is a perfectly common and acceptable pronunciation, it can only really be understood as an anglicization of [leɪtɛx] rather than the canonical pronunciation.
Here are the inept pronunciation instructions on the LaTeX project website:
> «Lah-tech» or «Lay-tech» (to rhyme with «blech» or «Bertolt Brecht»)
The pronunciation of the 'ch' in 'blech' isn't really standardized, so that's not much help. If we go by the German pronunciation of Brecht then the sound should be [ç], i.e. a voiceless palatal fricative. But this seems to be a mistake, as Knuth intended the X in TeX to be [x], i.e. a voiceless velar fricative. In German, [ç] is an allophone of /x/ (conditioned by the preceding vowel), but they are distinct sounds, and Knuth's directions for the pronunciation of TeX unambiguously specify [x]. It seems unlikely that this difference between the X in LaTeX and the X in TeX is intentional, so maybe this was a confused attempt to identify the [x] sound.
Really then, it's anyone's guess how LaTeX is supposed to be pronounced, since no-one with authority to specify has bothered to look up the IPA symbols for the relevant speech sounds. But IMO while [leɪtɛk] is a perfectly common and acceptable pronunciation, it can only really be understood as an anglicization of [leɪtɛx] rather than the canonical pronunciation.