In both words, the s sounds like [z].

The ‘s’ is pronounced [z] in these cases because it is between two vowels but you should be careful because there are a few exceptions.

They are relatively easy to spot if you are able to detect that the word is a concatenation of a prefix (or another word) and a word that starts with an ‘s’, e.g.:

• parasol
• vraisemblable
• désolidariser (but désolé = [dezɔle])
• dysenterie (but dysurie, an exception in the exceptions…)
• asocial
• resalir

Note that the word abasourdi is very often mispronounced by native French speakers with an [s] while it must be pronounced with a [z].