Voicing –occurredin the 16th c. (NE) to fricatives: in functional words and auxiliaries that are never stressed;
when preceded by an unstressed and followed by a stressed vowel.
| ME Sounds | NE Sounds | ME | NE |
| [s] à | [z] | possess [pə’ses] | possess [pə’zes] |
| [q] à | [ð] | this [qis],the [qə], there [qεə] | this [ðis],the [ðə], there [ðεə] |
| [f] à | [v] | of[of] | of[ov] |
| [ks] à | [gz] | anxiety [,ən’ksaiəti] | anxiety [,ən’gzaiəti] |
| [t∫] à | [dζ] | knowledge [‘kno:lət∫ə] | knowledge [‘no:lidζ] |