I can relate to this somewhat. I am hypersensitive to certain sound frequencies.

I can hear some things loud such as music but other sounds, such as hearing an infant scream or cry loudly, hearing a car horn honk loudly, hearing police sirens, somebody knocking loudly on my door, or having somebody talk loudly close to me or yell at me I find triggering and agitating.

With that being said, I don't think having sensitivity to loud noises particularly means that you have autism. I think there could be other possible reasons. Then again, it's always best to consult a mental health professional to be sure.

Personally though, I think Autism and Asperger's is thrown around way too liberally as a diagnosis, particularly with children. Just because somebody has some behaviors or personality traits that differ from the norm or is a bit more introverted or socially awkward than usual or has a higher IQ than most people doesn't mean they're autistic.