I agree, If it's occasional then it's like hunmas, some sneeze loudly, others don't.
My Beau has occasional very loud sneezes. His sound like a high pitched squeak (like Sweep from Sooty and Sweep) but is so loud it always makes us all jump.
In fact it was the lack of reaction to one of Beau's loud sneezes that alerted us to Pursley's deafness!
He's been doing this all his life, and now he's 13 things haven't changed at all, so we don't worry about him, it's just him