If someone says "excuse me" in an angry voice, it's sarcastic. If someone says "excuse me" in a soft voice, it's genuine. Or something like that, anyhow. It'

If someone says "excuse me" in an angry voice, it's sarcastic. If someone says "excuse me" in a soft voice, it's genuine. Or something like that, anyhow. It's certainly possible to make it ambiguous, in which case it will simply be interpreted according to the mood of whoever hears it.