Intelligibility of stereo and 3D-audio call signs for fire and rescue command operators

Abstract

A command operator of fire and rescue units may need to pay attention to several radio calls in the coordination of simultaneous emergency missions. An experiment investigated command operators' ability to discern stereo and 3D-audio call signs presented in background noise of added voice sources. Each of 10 command operators listened to one to four call signs combined with two to four background voices, with the primary task to discriminate the voice of each call sign. A secondary visual and manual response task induced an overall high mental workload. 3D-audio presentation resulted in a slightly increased number of correctly identified call signs. Four background voices reduced accuracy compared to two, and both three and four simultaneously presented call signs resulted in lower accuracy compared to sets of one and two, respectively. The results are discussed in relation to the potential for improving the 3D-audio presentation aiming for increased intelligibility and operator effectiveness.