What is the proper pronunciation of "kitten?"

The American Heritage Dictionary says 'KIT-n' but speakers in my locale (west coast US) say 'Ki with short i, glottal stop, n.' There is no 't' sound. Do we speak slang, a dialect, or are we pronouncing it correctly?

The only reference I found here was from last May: "Intervocalic /t/ almost always reduces to a single flap [ɾ] there. That’s why ladder and latter are homophonic, although kitten and kiddin’ are not. Indeed, kitten may become just [ˈkʰɪʔn̩] (sometimes written [ˈkʰɪʔən]) , often enough."

I don't understand IPA code. Thank you!

Just to clarify, slang describes a certain kind of vocabulary, and has nothing to do with pronunciation. Differences in pronunciation can be described in terms of accent. Dialect may describe differences in accent, but it is predominantly concerned with differences in vocabulary and grammatical structures.

In British English, the formal pronunciation of kitten is /ˈkɪt(ə)n/. It rhymes with Britain, and probably does so in American English as well, because, if both are pronounced differently from the British way, I imagine they do so consistently. Some regional accents replace the ‘t’ sound, both in kitten and elsewhere, with a glottal stop. In fact, most speakers will do so in certain phonetic environments. There’s nothing ‘incorrect’ about doing so.

I grew up in the tri-state area (NJ/NY/CT), CT specifically, and never realized I pronounced kitten differently until someone pointed it out. Also, mitten, smitten, etc. Primarily, we drop the tt's so it is ki'en, mi'en, etc.