In a study published in the Journal of the Acoustical Society of America, researchers from Western University in London, Ontario, explored the capabilities of surround sound reproduction using their custom AudioDome array. Ambisonics algorithms utilize dome-shaped speaker arrays to generate immersive virtual soundscapes. Surround sound systems can enhance the multimedia experience, but imagine a speaker setup that fully recreates a three-dimensional sound environment.

AudioDome is a loudspeaker capable of reproducing the entire surround sound field, allowing the listener to feel as if they are immersed in a real soundscape. Image source: sonible GmbH, Graz, Austria

The AudioDome is not just a speaker array, but a dome structure designed to provide immersive 360-degree surround sound. The system accurately reproduces the position and movement of sound sources coming from any direction when the listener is seated centrally.

Atmos rendering is a method of simulating the precise location of 3D sound using a speaker array. Atmos algorithms allow researchers to create rich virtual "soundscapes" that make each sound sound as if it comes from the precise location where it appears in the recording.

Researcher Nima Zargarnezhad said: "Ambient stereo technology promises to enable highly focused sound source reproduction, which will be valuable for researchers who wish to maintain tight experimental control while also studying auditory spatial perception in the complex, dynamic, three-dimensional soundscapes in which the human auditory system has evolved."

However, it is unclear whether the Ambisonics algorithm AudioDome uses to simulate soundscapes is suitable for studying human perception. This depends on the precision and focus with which it simulates the location of sound, and its ability to reproduce the energy content of sound. Since Zargarnezhad's team was interested in using the device for human experiments, they wanted to verify the effectiveness of the AudioDome's Ambisonics technology in simulating real life.

"We already knew that some reconstruction errors were predicted theoretically and confirmed through simulations, but we didn't know how and to what extent they would affect human perception of sound location and identity," Zargarnezhad said.

Humans' ability to distinguish between stimuli at different locations, known as spatial acuity, is higher in front of the face but decreases to the sides of the head. The researchers' experiments yielded very similar results from AudioDome listeners, demonstrating the speaker array's ability to reproduce sound location at spatial scales that exceed the limits of human perception.

They also found that simulating the location of soundsThe accuracy and precision do not depend on its distance from the actual speaker location, demonstrating that the spatial resolution of the ambient stereo algorithm is suitable for studying human perception almost anywhere in three-dimensional space. However, they also observed that the ambient stereo algorithm was able to accurately reproduce sound energy up to frequencies of about 4 kilohertz, which was enough to reproduce speech, albeit at a reduced sound level, as if heard over the phone. They showed that erroneous reproduction of high frequencies can falsify localization cues related to the perception of sound source height, while sources with high frequency content are perceived to originate from unexpected heights.

"We concluded that the Ambisonics algorithm is able to accurately reproduce the characteristics and location of many common sounds, including speech, with a spatial resolution that is even better than human spatial acuity," said Zargarnezhad. "This is sufficient to ensure that the reproduced soundscape accurately simulates the real world."

Compiled from /ScitechDaily