This study assessed sound localisation definition in ambisonic systems using two-non-parametric and three parametric decoders, in a two-dimensional format. The sound samples were played back through eight loudspeakers arranged in a circle. The participants compared pairs of sound samples to determine which sample offered a more precise perception of the sound source’s location. The data analysis, using a Bradley-Terry probability mode, revealed that parametric decoders were preferred with a 60–83% probability. Among the parametric decoders, the COMPASS method, which utilizes the Multiple Signal Classification algorithm for sound source direction estimation, received the highest scores for sound localisation judgements.

Here we report a photo−documented record of a barn swallow ( Hirundo rustica ) from the South Shetland Islands. We also review previous records of passerine vagrants in the Antarctic (south of the Antarctic Convergence Zone). This barn swallow is the first re− corded member of the Hirundinidae family on King George Island and is only the second passerine recorded in the South Shetland Islands. This sighting, along with previous records of austral negrito and austral trush represent the southernmost sightings of any passerine bird anywhere in the world.