Psychoacoustics project - Comparing auditory lateralization over near-field loudspeakers and headphones

My final psychoacoustics project had to be an experiment or study of some sort.

I compared people's accuracy in localizing sound on headphones and loudspeakers. Pretty straightforward, but the results were a bit crazy!

Lateralization while using headphones is more accurate than using loudspeakers? Just about, apparently!

Human listeners are capable of locating a sound source in the environment very precisely. For sounds on the frontal horizontal plane (right-left in front of the head) interaural time differences (I.T.D.s) between the two ears are the major cue in lateralization below 1500Hz, while interaural level differences (I.L.D.s) are how we better localize sounds above this frequency band. [7]

In my study, I am comparing people’s ability to lateralize (or ‘place’) sounds in a free-field situation (listening over loudspeakers) with a ‘closed’ situation (listening using close-backed headphones).

Many studies have been made into lateralization of sounds with I.T.D. and I.L.D. using headphones as a sound emitting device [1] [3] [4]. Studies have also been made into lateralization of sounds using loudspeakers [5] [6], but there haven’t been collaberative studies which compare the lateralization cues of both headphones and loudspeakers using clicks as auditory stimuli.