Lingua::en::syllable::syllable() estimates the number of syllables in the english word passed to it.

note that it isn't entirely accurate... it fails (by one syllable) for about 10-15% of the words. the only way to get a 100% accurate count is to do a dictionary lookup, so this is a small and fast alternative where more-or-less accurate results will suffice, such as estimating the reading level of a document.