What is an audio channel
"What is mono audio?" is a fairly common question for the average user. Many only learn the meaning when they start working with audio files, but in fact, it’s quite simple – mono audio indicates the amount of audio channels in a file.
An audio channel, simply put, is a representation of an audio signal in recording, playback, or mixing processes. In the context of playback, if there is more than one channel, they can carry different audio elements. For example, that is the way left and right speakers in stereo audio work.
Creating multichannel audio is not that hard, as it only requires recording sound from different microphones or sources. In filmmaking, for example, audio tracks for each object in the scene (footsteps, dialogue, sounds of nature) are recorded separately. Later, the recordings are mixed together during video editing.
Types of audio channels
When navigating this topic, many may wonder, is mono audio better than stereo? However, the mono vs. stereo debate is easily resolved – the efficiency of the channel type varies depending on their number and purpose.
For example, mono, or 1-channel audio, represents sound transmitted through a single channel, so it’s the same for both speakers or headphones. Mono audio is typically used in podcasts, lectures, and audiobooks, also in videos with an emphasis on speech elements (like educational videos or interviews).
In stereo, the 2-channel audio, the transmission occurs between left and right channels. It results in a sense of depth and direction, especially in recordings where the sound moves from left to right at some point. Stereo is the most common channel type for music, movies, and TV series, as well as video games.
Then, there is 5.1, a surround sound system with 6 channels. As the number suggests, it consists of five channels for main sound and one channel for low frequencies. Due to the greater sound depth it provides, 5.1 is a common system for film theaters, Blu-rays and DVDs, and video games that support surround sound.
The 7.1 system is a natural continuation of 5.1, as it comes with two more left and right rear channels. This addition brings even more details to the sound with an enhanced "three-dimensional" effect. It may be an overkill for an average user, so its main area of use is in cinema and premium home audio systems, games with advanced sound environment support, and professional film and music production.
It then continues to evolve into 9.1 and above high-end audio systems. Those are advanced multi-channel systems that add speakers for side and ceiling sounds (e.g. Dolby Atmos). Their inclusion makes a listener able to hear the sound not only around them but also from above, which enhances the feeling of presence and gives a more realistic sound immersion.
Apart from those systems, there is also binaural audio, a special method of recording and playing sound that imitates the natural perception by human ears. When someone listens to such audio, they hear the sound as if they were directly at the recording location. Due to such a realistic effect, it is widely used in Virtual Reality (VR). Creators can also use binaural audio to record immersive audio podcasts or experiment on musical recordings with 3D Sound.
Audio channels for streaming (AAC, OGG) are also worth mentioning. These are channels optimized for transmitting audio over the Internet, which allows data compression without significant quality loss. This leads to bandwidth savings and fast playback in real-time for maximum convenience for the listener. Such channels are used on platforms like YouTube, Spotify, and Twitch, as well as in video calls via Zoom or Skype.
FAQs
What is an audio channel?
In the field of audio recording and mixing, a "channel" refers to a single stream of audio signal that can be recorded, played back, or edited.
What is the best channel setup for YouTube videos?
For most YouTube videos, stereo (2 channels) is the preferred choice as it provides a deeper, more interesting sound that is suitable for a wider audience. More advanced audio settings are also plausible, but the creator should use them knowingly and with clear intent.
What equipment is needed to record stereo or multi-channel audio?
Stereo recording requires only two microphones and a simple audio interface. Multichannel recording requires significantly more equipment, including multichannel microphones, audio interfaces, and specialized software for mixing surround sound.
Conclusion
Although mono audio is still widely used, multichannel audio is usually preferred, as it significantly improves the perception of sound, making it more voluminous and realistic. Depending on the idea and capabilities of the creator, the use of multichannel audio allows the creation of the most immersive atmosphere for the listener and engages them in the main feature of video or audio.
