I personally would agree with "noch". Bust out the phone book and make a call to someone that lives there. "Is this Turd Ferguson of Noch street?" "Why yes it is. Why do you ask?" "Sorry, wrong number." Done.
I expect the street is named after Grace F. Knoche. She was born in the US, and since she taught amongst other things Hebrew and Qabbalah, I suspect (although I don't actually know) that she is from a Jewish background, and her name is from either Yiddish or German.
How you pronounce the street name thus depends on how the Knoche family pronounce their name. If they kept the German or Yiddish pronunciation, it would be "k'noch-a", with the "ch" pronounced as a rasping noise in the back of the throat (like the Spanish J, or the sound in the middle of "Mexico" when spoken by a Mexican), and the "k" clearly pronounced -- but without a vowel between the "k" and the "n".
However, that's almost impossible for a native speaker of English to pronounce correctly, so the Knoche family may have adapted the pronunciation. You'd have to find out how Grace Knoche herself pronounced her own name. But generally speaking, it's a safe bet to gow with whatever the residents themselves say.