Translation:Sixty people are going to prison.
What's the difference between "sześćdziesiąt osób" and "sześćdziesiąt ludzi"?
'Sześćdziesiąt ludzi' is incorrect, you should really say 'sześćdziesięcioro ludzi' instead.
The meaning is the same.
you can also say sześćdziesięciu ludzi - less female friendly (sześćdziesięcioro suggests mixed gender, sześćdziesięciu implies men only )but is less tongue twisting
osoby are easier to count then ludzie so when it's impied humans=person=people Poles rather use that word.
Most numbers take Genitive, and then they need the verb to use a singular form. The only ones that take Accusative (and a plural form of a verb) are those that end in -2, -3, -4 (but NOT those ending in -12, -13, -14).
Sounds fine to me, especially for a TTS.
Note that while they are almost never any 'vanishing' sounds in Polish, in this case it's a bit too much to pronounce "sześćdziesiąt" so clearly, so ć indeed isn't pronounced usually.