Masked thresholds were measured for five subjects in an anechoic chamber. The signal (a 500-Hz tone, an 8000-Hz tone, or a broadband noise) was presented from a movable loudspeaker located in the horizontal plane at ear level. A continuous noise masker came from two fixed loudspeakers at±14°azimuth. In different threshold runs the signal was either stationary (positioned at 0° or at 15° azimuth), or it moved during its on-time (at a velocity of 30°/s or 90°/s) through an arc from−15°to+15°.There was no evidence that any of the moving signals was more detectable than a stationary signal when threshold variation due to position changes of the stationary signal was taken into account. Likewise, there was no evidence that signal velocity affected detectability when signal duration was taken into account. These results agree with previous reports obtained with simulated moving signals presented via earphones and suggest that if horizontal motion-sensitive mechanisms exist in the auditory system, such mechanisms do not contribute to signal detectability.