Surround sound

Sound can come from all around you.

This is called surround sound. It uses many speakers at once.

Some speakers sit in front of you. Other speakers sit at your sides or behind you. This makes sounds feel like they are moving.

In a movie theater, this helps you feel part of the story. It can even make a bee sound like it is flying near your head.

You can use this for music or video games, too. It makes the world around you feel very real.

Have you ever felt like a sound was moving around you? This is called surround sound. It uses many speakers to make sound feel deep.

Instead of sound coming from just one spot, it comes from all sides. This uses sound localization. This is our ability to tell where a sound is coming from.

Most people use a setup called 5.1. This is a standard way to set up six speakers. One speaker stays in the center. Two speakers go in the front at angles. Two more speakers go at your sides. The last speaker is a subwoofer. A subwoofer is a speaker for low sounds.

Surround sound started in movie theaters. Disney used it in the film Fantasia. They wanted a bee to sound like it was flying.

Today, we use it for more than movies. It helps with music and video games. It can even help people in the military. It makes the world around you feel very real.

Surround sound is a special way to make audio feel deep and real. Instead of sound coming from just one place, it comes from many directions. This technique uses multiple audio channels to send sound to many speakers. These speakers are placed all around the listener to create a ring of sound.

This works because of sound localization. This is the way our ears can tell where a sound is coming from. It helps us know both the direction and the distance of a sound.

To make this happen, engineers use an array of different loudspeakers. Each speaker plays a specific part of the audio. A common way to do this is the 5.1 standard. This setup uses six different speakers to build the sound field.

One speaker is the center channel placed right in front of you. Two speakers sit at 60-degree angles to your left and right. Two more speakers sit at your sides at angles between 100 and 120 degrees. Finally, a subwoofer handles the low sounds, though its exact spot does not matter as much.

People have been working on this for a long time. The first documented use was in 1940 for the Disney film Fantasia. Walt Disney wanted a bumblebee to sound like it was flying around the whole theater. This early version was called Fantasound and used about 54 loudspeakers.

Later, in 1967, the band Pink Floyd performed the first surround sound concert. They played at the Queen Elizabeth Hall in London. They even used a special tool called the Azimuth Co-ordinator to help manage the sound.

There are many different ways to record and play these sounds today. Some systems use many speakers to create an "audio hologram." One method is called wave field synthesis, or WFS. This uses a lot of computing power and many speakers to rebuild a sound field.

Another common method is called Ambisonics. This is very popular with musicians and for computer music. Other formats you might see include Dolby Digital or DTS in a movie theater. Some high-end systems like Blu-ray use lossless audio to keep the sound exactly like it was in the studio.

Surround sound is used in many parts of our lives. It is not just for watching movies in a big cinema. You can find it in video games, computers, and even music.

It can even be used in museums to make an exhibit feel real. For example, an exhibit might play the sounds of birds or trains. In the military, it can help people stay aware of their surroundings. It turns a simple sound into a whole environment that you can step into.

Surround sound is a sophisticated audio technique used to increase the depth and fidelity of sound. It works by using multiple audio channels played through an array of loudspeakers. These speakers are positioned to encircle the listener, known as the surround channels. This setup creates a sensation of sound moving in any horizontal direction around the person. The goal is to enhance sound spatialization, which is the way we perceive the location of audio.

This relies on sound localization, the human ability to identify the direction and distance of a sound source.

To achieve this effect, engineers use many discrete audio channels. Most systems have a specific listening area called a sweet spot. At this location, the audio effects work most effectively for the listener. The system presents a fixed or forward perspective of the sound field to the person in that spot.

By routing different sounds to different speakers, the technology can make a listener feel like they are inside the environment. This transforms a simple recording into a three-dimensional experience.

One of the most common setups is the ITU 5.1 standard. This configuration requires six specific components to function. It includes a center channel (C) placed directly in front of the listener. There are also left (L) and right (R) speakers positioned at 60-degree angles. Two surround speakers, left (LS) and right (RS), are placed at angles between 100 and 120 degrees.

Finally, a subwoofer is used for low-frequency effects, and its exact position is not critical.

More complex systems, like 7.1, add two more rear speakers to create a 360-degree sound field.

The history of this technology is filled with experimental breakthroughs. The first documented use was in 1940 for Disney's film Fantasia. Walt Disney used a system called Fantasound to make a bumblebee sound as if it were flying around the theater. This early system used about 54 loudspeakers to diffuse sound.

In 1967, the rock group Pink Floyd performed the first surround sound concert at London's Queen Elizabeth Hall. They used a custom quadraphonic speaker system and a control device called the Azimuth Co-ordinator. This device is now part of the collections at the Victoria and Albert Museum.

Engineers use several different methods to create these immersive environments. One way is through specific recording techniques, such as using an augmented Decca tree. Another approach uses psychoacoustic methods to simulate a 2-D sound field using headphones. Some advanced systems use Huygens' principle to reconstruct sound wavefronts, creating an "audio hologram." One version of this is wave field synthesis, or WFS, which requires many speakers and high computing power. Another common method is Ambisonics, which is widely used by musicians and in computer music. Ambisonics provides an exact sound reconstruction at the central listening point.

Surround sound is applied across many different industries and media types. In cinema, formats like Dolby Digital and DTS are standard. High-definition media like Blu-ray use lossless audio, such as Dolby TrueHD, to match the studio master.

Beyond movies, it is used in video games and personal computers to create synthetic noises that react to the user. It is even used in museums to enhance exhibits with ambient sounds like birds or machines. In the military, these techniques can help improve situational awareness for public safety.

Finally, surround sound allows for new forms of artistic expression in music. While quadraphonic audio failed in the 1970s, multichannel music returned in 1999 through formats like SACD and DVD-Audio. Some modern devices even use digital signal processors to perform "upmixing." This process takes a standard stereo recording and uses software to parse individual sounds into a five-channel field. This allows older music to be experienced in a more modern, spatial way.