Is 3D audio just surround sound?
3D audio and surround sound are two technologies designed to provide an immersive audio experience for listeners. They aim to make listeners feel like they’re in the middle of the action by simulating sound coming from all directions. While they share some similarities, 3D audio and surround sound work in different ways to create that illusion of space.
Surround sound uses multiple speakers placed around the listener to play audio channels. The separation of channels creates the feeling of directional sound. 3D audio goes beyond surround sound by also tracking the listener’s head movements and adjusting the audio in real time. This enables sounds to stay fixed relative to their position in the virtual space as the listener moves around.
In this article, we’ll explore the key differences between 3D audio and surround sound, including how they work and examples of the technologies being used today.
What is Surround Sound?
Surround sound refers to audio reproduction technologies that aim to create a 360-degree sound field around the listener. The goal is to make listeners feel like they are immersed in the sound by surrounding them with audio from multiple directions.
The origins of surround sound date back to the 1930s when engineers experimented with multichannel sound for films. Walt Disney was one of the early pioneers, developing technologies like Fantasound for films like Fantasia to create a more immersive experience. In the 1950s and 60s, technologies like stereo sound and quadraphonic audio advanced surround sound for both film and music.
The basic principle behind how surround sound works is distributing audio signals to multiple speakers placed around the listener to make it seem like sounds are coming from various directions. A surround sound system typically consists of front left, front right, center, surround left, surround right, and a subwoofer channel for deep bass. Advanced systems may add more speakers like front height, rear height, and more.
The audio engineer mixes different elements like dialogue, sound effects, and music to different channels to create an immersive 360-degree soundscape. When properly calibrated, this allows listeners to perceive sounds coming from all around them, as if they were in the movie scene or concert hall.
Over the decades surround sound technologies like Dolby Atmos, DTS:X, Sony 360 Reality Audio, and others have aimed to make the experience even more immersive by adding speaker channels, 3D audio, and more advanced mixing techniques.
What is 3D Audio?
3D audio, also known as spatial audio, refers to sound that is processed to give the perception that it is coming from a particular direction or location. The goal of 3D audio is to immerse the listener in a more realistic and enveloping sound experience compared to standard stereo audio.
The origins of 3D audio can be traced back to the late 19th century with the invention of binaural recording techniques that aimed to capture the spatial properties of sound. As explained by Dear Reality, “Binaural literally means ‘hearing with two ears.’ Binaural audio recording uses two microphones to capture sound from two positions, similar to human ears” (Source). This creates a 3D soundscape when listened to with headphones.
Modern 3D audio utilizes advanced digital signal processing to position sounds in a three-dimensional space. As the New York Times describes, spatial audio introduced “object-based audio, in which sounds are placed as individual objects that can move dynamically throughout 3D space” (Source). This allows for a more immersive audio experience beyond static channel-based audio like stereo.
Overall, 3D audio aims to give a sense of space, distance, and direction to sounds, placing the listener at the center of an immersive spherical audio environment.
Key Differences
Though surround sound and 3D audio may seem similar at first glance, there are some notable differences between the two technologies (Microsoft Research).
3D audio is more advanced and immersive than surround sound. While surround sound relies on a set number of discrete speakers placed around the listener, 3D audio can replicate a fully three-dimensional soundscape over headphones or even standard stereo speakers. This allows for more precise positioning of sounds and a more enveloping listening experience (Reddit).
Additionally, 3D audio does not require a specific multichannel speaker setup in order to achieve its effects. The 3D positioning is encoded into the audio itself rather than relying on speaker placement. This makes it much more accessible and flexible versus surround sound systems which need proper speaker configuration to work (Audio Theory Training Manual).
Finally, 3D audio is focused on modeling real-world acoustic properties and environments. Advanced 3D audio systems simulate how sounds reflect and interact with environments to create an exceptionally realistic and immersive experience. This level of acoustic modeling is not present in basic surround sound systems.
3D Audio Technologies
There are several key 3D audio technologies on the market today:
Dolby Atmos – This technology allows sound to be positioned and moved in a three-dimensional space. Speakers send audio to specific locations around a room, creating an immersive experience. Dolby Atmos can support up to 128 tracks and 64 speaker channels [1].
DTS:X – Similar to Dolby Atmos, DTS:X enables surround sound audio objects to be dynamically distributed in 3D space. It adapts audio rendering based on the speaker setup, providing immersive sound regardless of configuration [1].
Sony 360 Reality Audio – This format focuses on optimizing music for spatial audio. It analyzes sound sources and spatial information to produce a three-dimensional sound field. Listeners can experience music as if they were at a live concert hall or studio [2].
There are also other 3D audio technologies like Auro 3D and Binaural Audio that aim to create immersive listening experiences. Overall, 3D audio goes beyond standard surround sound by truly enveloping the listener in a sphere of audio.
Uses of 3D Audio
3D audio is being used in a variety of applications to create more immersive experiences. Some of the main uses are in music, movies, gaming, and virtual and augmented reality.
In music, 3D audio allows songs to move around the listener and utilize height channels to create a surround sound experience. Artists like Bjork have experimented with spatial music using 3D audio technologies.
For movies, 3D audio can make viewers feel like they are right in the middle of the action. It allows sounds to move around the theater and accurately portray distance and direction. Dolby Atmos is one of the leading 3D audio formats being used in theaters.
Gaming also benefits greatly from 3D audio by increasing immersion. Players can more accurately pinpoint sounds and tell what direction they are coming from. Sony’s Tempest 3D audio has been implemented in PS5 games.
In virtual and augmented reality, 3D audio is crucial for creating truly immersive experiences. It allows the virtual world to come to life with spatialized sounds that react realistically as users move and interact.
Challenges of Adoption
While 3D audio offers exciting possibilities, there are still challenges to mainstream adoption. Two key challenges are hardware/software requirements and limited content availability.
To experience the full benefits of 3D audio, advanced and specialized hardware is often needed, such as surround sound speakers or spatial audio headphones. The processing power required for 3D audio is also greater compared to standard stereo audio. This means that consumer devices like smartphones may struggle to render 3D audio optimally (Source).
There is also a lack of content mixed and available in 3D audio formats. The number of music albums, movies, games, and other media produced in 3D audio is still relatively small compared to traditional stereo. This limits the accessibility and exposure of 3D audio to the general public. However, with spatial audio support in services like Apple Music, there is growth in 3D music content that may help overcome this challenge (Source).
The Future of 3D Audio
In the years ahead, we will likely see even more growth in 3D audio technology and its adoption. As hardware and software continue to improve, more devices will support 3D audio playback, making it more accessible to consumers. Movies, music, and video games will increasingly incorporate 3D audio to provide more immersive experiences. Over time, 3D audio may become commonplace across various forms of entertainment as the technology matures.
Industry experts predict that 3D audio is poised to become a mainstream standard, rather than a niche feature. As it becomes more affordable and widespread, audiences will come to expect and demand 3D audio for the most engaging entertainment. From virtual reality to live concerts, 3D audio can transport listeners into the middle of the action. The sense of space, depth, and realism offered by 3D audio will likely make it a key part of future entertainment experiences.
Conclusion
Surround sound and 3D audio may seem similar at first glance, but they represent two distinct advancements in audio technology. Surround sound spreads sound around multiple speakers, usually in a 5.1 or 7.1 configuration. This creates an immersive experience by encircling the listener.
3D audio goes beyond surround sound by adding height channels, object-based mixing, and head-tracking. This allows for precise placement of sounds in a fully three-dimensional space. The listener perceives sound as occurring above, below, and all around them.
While surround sound aims to immerse the listener in a broader soundfield, 3D audio strives to recreate a real-world acoustic environment. Sounds can be pinpointed at specific coordinates in space, as in real life. This leads to greater realism and localization of audio sources.
Both technologies enhance the listening experience in their own way. Surround sound provides a broader, more enveloping effect while 3D audio brings pinpoint precision and height to the soundscape. As 3D audio matures, it stands to eventually supersede surround sound and become the new standard for immersive audio reproduction.
What is Surround Sound?
Surround sound refers to an audio system that uses multiple speakers to create a 360-degree sound field around the listener. The goal of surround sound is to make audio feel more immersive and lifelike.
Most surround sound systems use 5 speakers – left, center, right, rear left, and rear right. These are placed around the listener to envelop them in sound. Advanced surround systems may use up to 7 or 9 speakers.
Surround sound takes a stereo audio track and processes it to send different elements of the audio to different speakers. This allows sounds to come from all directions, as they would in real life. For example, dialogue may come from the center speaker, while ambient sounds come from the left and right.
The additional speakers make audio feel more three-dimensional and spatial compared to regular stereo. However, surround sound still provides a fixed listening position and lacks the ability to replicate how sound waves propagate in real environments.