This study assessed the effects of spatialized sound presentation on a listener's ability to monitor target (T) messages in the presence of competing (C) messages and high-level (110 dB[A]) background noise (BGN). In a simulated military environment, 8 participants wore two-channel, active noise reduction (ANR) equipped helmets and listened to combinations of T and C messages (89 dB[A] at the ear). T messages were presented synchronously with 0, 1, 2, and 3 C messages in four listening modes: (a) BGN + diotic, (b) BGN + dichotic, (c) BGN + spatial audio, and (d) quiet + spatial audio. Best overall performance occurred in the spatialized modes (c and d) and poorest in the diotic mode (a). As expected, speech recognition was better in quiet than in BGN when multiple C messages were present. Findings indicate that message spatialization in acoustic space improves auditory performance during times of heavy message competition, even in high-level noise. The proposed technology has numerous applications, such as multichannel communications in tactical operations centers, monitoring of complex security systems, and air traffic control.