s voicing

Core Rule

S-voicing occurs when s shifts from /s/ to /z/ in voiced environments, typically between vowels or after voiced sounds, improving speech flow.

Articulation

Tongue near the alveolar ridge, relaxed lips, steady airflow with vocal cord vibration.

Examples

presence /ˈprezəns/ (vowel-surrounded), symposium /sɪmˈpoʊziəm/ (pre-stress voicing), transistor /trænˈzɪstər/ (after /n/).

Pitfalls

Do not rely on spelling alone; listen for voicing context.