Have you ever wondered how we can tell which direction someone is facing just by hearing their voice?
A group of researchers in Japan recently explored this question, and their findings could help improve sound quality in virtual reality (VR) and augmented reality (AR) experiences.
The study was led by Dr. Shinya Tsuji and his team from Sophia University and NHK Science and Technology Research Laboratories.
They wanted to find out how people judge the direction a speaker is facing using only sound, without any visual clues.
This is especially important for virtual environments, where realistic sound can make digital experiences feel much more lifelike.
To investigate, the team ran two experiments. In the first, they used voice recordings that varied in loudness depending on which way the speaker was facing. In the second experiment, they removed loudness differences to see if people could still guess the speaker’s direction.
Not surprisingly, people were better at figuring out the direction when loudness changed with the speaker’s position. In real life, someone sounds louder when they’re facing you and quieter when they turn away.
But what’s interesting is that even when all the recordings were played at the same volume, participants still managed to guess the speaker’s direction better than chance. This means we also rely on other parts of the sound—such as changes in pitch and tone, known as “spectral cues”—to understand where a voice is coming from.
Dr. Tsuji explained that while loudness is the most obvious clue, the shape and quality of a person’s voice also shift subtly depending on how they are turned. These small differences give our brains extra information to work with.
This research is especially relevant today, as immersive technologies like AR and VR are becoming more common. Devices such as Meta Quest 3 and Apple Vision Pro use 3D audio to create realistic digital worlds.
In these environments, users can turn their heads, move around, and hear sounds from different directions—just like in the real world. Making voices sound as natural and directional as possible can greatly improve these experiences, whether you’re in a virtual meeting, watching a movie, or playing a game.
Beyond entertainment, these findings may also help improve accessibility for people with vision loss, or support more engaging virtual therapy sessions.
By understanding how we perceive the direction of sound, developers can design better and more believable digital soundscapes.
In short, our ears are smarter than we think.
Even without seeing someone, we can often tell where they’re facing, just from the way their voice sounds—and that knowledge is helping shape the future of virtual reality.
Source: KSR.
