Speech Work: Contrasting Consonants /s/ and /z/

The /s/ sound:

/s/ – The blade or tip of the tongue is in contact with the alveola ridge and this obstructs the flow of air with no vibration as a result of the widening of the vocal tract. It is a voiceless sound and the spelling symbols occur in all three positions. 

“c” – cell, cite, pencil

“s” – basic, sew, basis

“ss” – mass, essay, ass

“sc” – science, scent, descent

“se” – mouse, cease, base

“ce” – ice, price, nice

The /z/ sound:

/z/ – The blade or the tip of the tongue is in contact with the alveolar ridge, causing an obstruction to the outflow air, with vibration, as a result of the narrowing of the vocal tract or cords. It is a voiced sound and the spelling system for /z/ are as follows:

“z” – zoo, zebra, zeal

“x” – exact, examine, exit

“s” – has, cousin, phrase, phase

Word contrast between /s/ and /z/

/s/	/z/
seal	zeal
ice	eyes
close	doze
price	prize
since	sins
sink	Zinc