If you're on Twitter ask the Roman historian Mary Beard (@wmarybeard) if she can, and if she can't, if she'd be so kind as to retweet to Egyptologists.
All I know about hieroglyphics is that they're a mixture of ideographs and phonetic symbols, so the symbol for the word for 'cat' is the sounds for miaou with a cat ideograph as a signifier at the end. Or something like that. But that's how we know that the ancient Egyptian word for cat was pronounced 'meow'.