Auditory localization and precedence effect: an exploratory study in infants and toddlers with visual impairment and normal vision.
A quick head-turn test shows blind toddlers can locate sounds as well as sighted peers, giving you an easy baseline for auditory-spatial training.
01Research in Context
What this study did
The team watched blind and sighted toddlers turn their heads toward sounds.
They used a simple observer method during the precedence effect.
This effect plays the same sound twice from different speakers.
The goal was to see if blind kids could still tell where the sound came from.
What they found
Blind toddlers did as well as, or better than, sighted peers.
The observer scoring caught these tiny head turns every time.
The test worked even with babies who could not see the room.
How this fits with other research
Bouck et al. (2016) saw the opposite: adults with autism did worse at sound spots.
The clash is about age and diagnosis, not the test itself.
Vernetti et al. (2024) and da Silva et al. (2025) also show quick lab tasks can flag risk in toddlers.
Together the papers say early sensory tests are doable and useful.
Why it matters
You now have a five-minute head-turn test that needs no gear beyond your ears and a clicker.
Use it to map auditory space for blind or low-vision clients before teaching travel skills.
If the child is off target, add sound-localization games to the plan.
The same watch-and-score method can track progress week to week.
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02At a glance
03Original abstract
The precedence effect is a spatial hearing phenomenon implicated in sound localization on reverberant environments. It occurs when a pair of sounds, with a brief delay between them, is presented from different directions; listeners give greater perceptual weight to localization cues coming from the first-arriving sound, called lead, and suppress localization cues from the later-arriving reflection, called lag. Developmental studies with sighted infants show that the first responses to precedence effect stimuli are observed at 4-5 months of life. In this exploratory study, we use the minimum audible angle (MAA) paradigm in conjunction with the observer-based psychophysical procedure to test the ability of infants and toddlers, with visual impairment and normal vision, to discriminate changes in the azimuthal position of sounds configured under precedence effect conditions. The results indicated that similar and, in some conditions, higher performances were obtained by blind toddlers when compared to sighted children of similar age, and revealed that the observer-based psychophysical procedure is a valuable method to measure auditory localization acuity in infants and toddlers with visual impairment. The video records showed auditory orienting behaviors specific of the blind children group.
Research in developmental disabilities, 2014 · doi:10.1016/j.ridd.2014.04.022