Polyphony versus homophony

The noun polyphony derives from the Greek words polys (many) and phone (voice, sound) and means “variety of sounds” [1]. With the Greek word homos for “same,” the noun homophony means “sameness of sounds” or “monotony of sounds.”

In linguistics, polyphony is a special form of polyvalence, which refers to the assignment of multiple values (meanings) to a written sign. The term polyphony stands for the multiplicity of sounds associated with a hieroglyph, symbol or character (and sequences thereof) belonging to the writing system of a spoken language [2]. For example, the letter combination ow is polyphonic: note its different pronunciation in the words towel, tow and tomorrow.

Homophony is the converse of polyphony. Michael Coe provides a striking example of homophony found in Mayan writing—originally presented by the epigrapher Stephen Houston [2]: Three significantly different looking glyphs, which are the signs for “four,” “snakes” and “sky,” have the same sound can (Yucatec language) or chan (Cholan language). Any of these three homophonic signs may occur as logograph in a phrase whenever this sound is required. This example further demonstrates the phoneticism of the Mayan writing system: although the hieroglyphs may have ideographic or semasiographic roots, they often “evolved” to represent specific sound values.

Keywords: linguistics, language, pronunciation, sign substitution, symbol substitution, glyph interchangeability, Maya homophony, spelling.

References and more to explore
[1] Online Etymology Dictionary: polyphony (n.), polyphonic (adj.) [http://www.etymonline.com/index.php?allowed_in_frame=0&search=polyphony&searchmode=none].
[2] Michael D. Coe: Breaking the Maya Code. Thames & Hudson, New York, Revised Edition 1999; page 235 and Glossary.