Are there any silent letters in Latin?

Well, according to some historical phonologists, W S Allen is perhaps the most accessible, the final s in most words had ceased to be pronounced in the late Republic. Final m was probably just a hint of nasalization on the vowel it followed amd finally disappeared some time before Silver Latin (say the Fall of Rome).

Latin distinguished the quality of vowels, i.e., between long and short vowels. For instance, all those metrical terms we learn in poetry class, anapest et al., were based on vowel quantity and not on stress (as they are in English today). The stress of a Latin word was dependent on these vowel qualities, too. Stress is usually on the ante-penultimate unless the penultimate is long. In the early version of the Classical pronunciation which I learned, long e was pronounced /e/ and short e was pronounced /E/; same with long and short i, /i/ and /I/. This is what happened later in the Romance languages that are descended from Latin. Though some of the long vowels became diphthongs when stressed: e.g., Italian buono, Spanish bueno from Latin bonus. What many speakers (and some singers) of English do that is right out no matter whether pronouncing classically or ecclesiastically is to use the modern-day English diphthongs (our so-called long vowels), e.g., /ej/ for e, /ow/ for o.

Ceci n'est pas un seing.