Are there any three syllable words which exist as a noun and verb?

There are several which don't follow the stress pattern:

• intercept
• interchange
• overcount / undercount

Here are a couple where the pronunciation between the verb and noun is consistently different:

• attribute (noun attribute; verb attribute)
• envelope (noun envelope; verb envelope), though the verb is usually spelt without the final "e".

I suppose "entrances" is also worth mentioning, but these are two separate words with unrelated meanings and separate etymologies.

The first syllable of “duplicate” is stressed as noun, verb, or adjective.  However, its pronunciation changes: similar to the “pre” in “present” and the “ope” in “envelope”, the “cate” in “duplicate” is pronounced as a “long a” (like “cape” or “cater”) in the verb, and like a “short i” (“kit”) in the noun and adjective.