I went to the USS Hornet to see a para-physiologicist named Llyod Auerbach speak. After his presentation the group was split up into teams and a paranormal investigation ensued. It was my first time ever doing such an activity and I had no idea what I was doing. I even had to borrow a flash light from someone else. Towards the end of the investigation around midnight I was located on the second deck of the ship just one compartment aft of the CPO mess. This area I'm referring to is very much towards the aft end of the whole ship just below an area called the fan tail. Out of no where came the sudden sound of what seemed to be a propeller based aircraft. I'm talking loud and getting fucking louder. Like 120 decibels fucking loud. There was another woman in the group who I did not know in the compartment. I looked at her and yelling to overcome the sound I asked if she could hear it. She replied no and as soon as she said no the sound stopped. I easily heard this sound for 6 to 8 seconds. Really was questioning my sanity at that point. Stayed there easily for another 20 minutes hoping that sound would return but no dice. I have personally chalked it up to unexplainable as it's the only way I can rationalize things. But to be honest fuck if I really know what happened. It did peak my interest and I did become a volunteer on the ship and worked there in ship restoration for the next 7 years.