A phonetic script is one where the symbols represent sounds. The Latin alphabet is a phonetic script. In contrast, consider the shared numeric system used in both English and Polish. How do you pronounce "1"? What about "10" or "11" - does using the same symbol in all three numbers give you any hint about whether they sound the same? What if I'm saying the numbers in French?

The answer is of course, no, those symbols don't have an associated sound. They have an associated meaning and there are many spoken words for that meaning.