The ornamental design for a wirelessaudiotransmissionsystem, as shown and described.
FIG. 1 is a stereogram of the second component;
FIG. 2 is a front view of the second component;
FIG. 3 is a rear view of the second component;
FIG. 4 is a left side view of the second component;
FIG. 5 is a right side view of the second component;
FIG. 6 is a top view of the second component; and,
FIG. 7 is a bottom view of the second component.
The broken lines are included for the purpose of illustrating portions of the wireless audio transmission system and form no part of the claimed design.