Urhobo has a rather reduced system of sound inventory compared to proto-Edoid. The inventory of Urhobo consists of seven vowels; which form two harmonic sets, /ieɛaoɔu/ and /ĩẽɛ̃ãɔ̃õũ/.
It has a conservative consonant inventory for an Edoid language. It maintains three nasals, and only five oral consonants, /ɾ,l,β̞,j,w/, have nasal allophones before nasal vowels.
/l/ is interchangeable with [n] only before nasal vowels.
/d͡ʒ/ can be heard as [ɟ͡ʝ~ʝ] before non-front vowels.
Nasal consonants /m,[n],ɲ,ŋ͡m/ can have allophones of nasalized approximants as [β̞̃], [ɹ̃~ɾ̃], [j̃], [w̃].
Approximants /β̞,j,w/ are heard as nasalized approximants [β̞̃,j̃,w̃] before and after nasal vowels.
Velar fricatives /x,ɣ/ can vary from being heard as [x,ɣ] to lowered fricatives [x̞,ɣ̞] and approximants [ɰ̊,ɰ]. /x/ can also be heard as a palatal fricative [ç] before /i/.
Rhotics /r̥,r/ may have different realizations as alveolar or retroflex, and can be articulated as approximants [ɹ̥,ɹ,ɻ̊,ɻ], or taps [ɾ̥,ɾ,ɽ̊,ɽ]. A retroflex lateral flap [ɭ̆] can also be heard in syllable-final position.
According to Anthony Ukere, Urhobo has two tones, a high tone and a low tone. These can also combine to form rising and falling tones. Rose Aziza is a professor of linguistics who does work on the phonology of Urhobo.
