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Real-time communication is an essential aspect of modern life. With faster internet connections and superior technology, communication has never before reached today’s high standards.
Unfortunately, remote communication technologies can’t always solve the problems that might occur in the process. These include echo, jitter, high latency, and others.
There are several reasons why an echo occurs, but regardless of the cause, the result is degradation of real-time communication. Echoes impair not only call quality but also can lead to an increased amount of bandwidth used. This is because more data is transmitted from the additional sound information coming from the echo.
In this article, we’ll discuss what echo cancellation is, natural ways of implementing audio echo cancellation that you can recommend to your users, and the value of software for echo cancellation.
Echo is considered to be a major contributor to poor voice quality in phone and video conversations. As a result, means to handle echo are an important part of any telecommunication system. Two key methods exist that help remove or mitigate echo and thus improve the RTC quality – echo cancellation and echo suppression.
Echo cancellers work by estimating the echo path from the transmitting end to the receiving end, and then using this estimate to generate an “anti-echo” signal that cancels out the echo.
Echo suppression is a method used to prevent various types of echoes from being created and captured. The echo could surface in the form of one’s voice transmitted back through the receiver’s speakerphone or audio being reflected around the room. An echo suppressor, which could be a physical device or software, is designed to mitigate and eliminate echo as a factor within calls.
This blog post uses echo cancellation and echo canceller as general terms for all echo-reduction methods and means.
Echoes can become a significant problem for users of your app. While some may decide to muddle through the problem, there are consequences to echoes during video calls, such as:
Previously, there were few viable solutions to tackle this problem. Today, there are more options for removing echoes than ever before.
Echo cancellation software is one way to minimize echoes. There are, however, other natural (non-software) methods that can minimize echoes during video communication.
In this section, we will look at two main types of echoes and what natural echo-reduction methods you can recommend to your users.
Acoustic echoes occur on the listener’s end because their microphone picks up sound coming from their speakers.
Hybrid echo occurs when a person speaks, and the sound of their voice is heard twice: once directly from their mouth and once after reflecting off of surfaces in the environment, such as walls or tables.
Overly sensitive microphones are notorious for causing echoes, which is often a symptom of either misconfiguring the hardware or a poor-quality microphone. Sound reflection can also cause acoustic echoes, such as if the listener is participating in a call or video within a confined space.
One solution you can recommend is to swap out an existing microphone for one with a narrow pickup direction. These microphones are designed only to pick up sound from the front while being unable to collect sound from other directions. These microphones also have the added benefit of avoiding too much ambient sound being collected.
Another option is to turn down the microphone’s volume to make it less able to pick up sound and reflect it back.
Production businesses may also choose to invest in acoustic foam. This foam contains an eggshell structure and texture that makes it more difficult for sound to reflect because there are no flat surfaces for sound to rebound off. However, these sound booths are a considerable expense that may be out of the budget of most users.
Finally, if a quick solution to acoustic echo is required, a user can switch from using speakers to using a set of headphones. Noise-canceling headphones are especially adept at limiting the impact of echoes.
Natural methods for canceling echo aren’t always a sufficient solution. But is an echo canceller the right way forward? Before you decide, it’s important to note that software for echo cancellation typically targets acoustic echoes only—not hybrid ones. Hybrid echo cancellation is a more complicated technique. This type of echo canceller uses both digital and analog processing techniques. It is more effective than either digital or analog echo cancellers alone but is also more complex and expensive. Hybrid echo cancellation is used in a variety of telecommunication systems, including VoIP (Voice over IP) and GSM (Global System for Mobile Communications). Acoustic echo cancellation must be used on both sides of a video meeting to combat echo successfully.
The concept of software for echo cancellation is straightforward to understand. The software picks up the incoming audio and determines that the signal being sent is the same one that went out. It identifies a match or a close match and electronically cancels the second one. The process happens in milliseconds in the background, thus allowing crystal-clear call quality.
Agora has always believed acoustic echo cancellation should be standard to facilitate clear, hassle-free communication within personal and business settings. With this in mind, Agora’s RTC SDK offers automatic echo cancellation that delivers high-quality calls every time.
There are other software-based solutions that may offer similar features. For example, some echo cancellers utilize software that is aimed at videos designed to be uploaded for future viewing. However, echoes are resolved during the post-processing stages.
While echo suppression within post-processing is a valuable tool, it fails to solve the problem of echo cancellation in real-time communication. Agora eliminates echoing during the pre-processing stage to create clearer communication right now.
As a leading real-time communication platform for developers, Agora understands that communication is the foundation of a user experience. Echoes compromise that experience by disrupting the transmission of video and voice. Whether you are a solo entrepreneur or a developer that is part of a larger organization, you can benefit from our Software-Defined Real-Time Network (SD-RTN™). The SD-RTN™ minimizes latency and packet loss by continuously monitoring and optimizing data transmission paths across millions of concurrent users. Even better, our easy-to-use, customizable products all support echo cancellation and call quality monitoring. Echo cancellation can be further enhanced with advanced features such as Agora AI noise suppression or Bose PinPoint noise filtering.
Agora is spearheading the future of real-time communication and user engagement with easy-to-use SDKs for Video Calling, Interactive Live Streaming, and Voice Calling that include echo cancellation.
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