Sound Barrier information:

sound barrier: The term sound barrier is often associated with supersonic flight. In particular, "breaking the sound barrier" is the process of accelerating through Mach 1 and going from subsonic to supersonic speeds. The term originated in the 1940s when researchers discovered a large increase in drag that seemed to indicate that an infinite amount of thrust would be needed to fly at the speed of sound. In other words, some believed that a physical barrier existed that would prevent an aircraft from ever being able to travel at supersonic speeds. Since there obviously is no such barrier, the term sound barrier is outdated and really should not be used any more. Nevertheless, it has become a popular part of the human language, and continues in use.

The speed of sound is a variable rate depending on the density of atmosphere. The general speed of sound at sea-level is 761.18 mph (1,224.74 km/h). At 102,000 feet, the speed of sound would be about 675 mph (1008 km/h).

Col. Kittinger easily passed the speed of sound at high altidude. As far as shock wave issues, clearly they were insignificant. I've talked with Col. Kittinger several times and he has never mentioned even the fear of the shock waves. That's about all I know. He went supersonic in "space" and probably returned to subsonic speeds well before he opened his chute, because of atmospheric friction (Goodness knows what it would be like to open a chute at 750 mph).