Echo Cancellation, Art or Science? Part V

  • On December 4, 2021
Background [EDITED] The following blog post provides an overview on all major components that are required when building/designing an echo cancellation software. In this post we will discuss a common implementation issue we have seen many times – audio stream synchronization.
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Flash Conference with Acoustic Echo Cancellation

  • On August 12, 2018
Background Following our previous post on acoustic echo cancellation on flash calls, we got requests to improve audio quality also on conference calls that are based on flash technology. The case study that was described in the previous post dealt with audio quality for regular flash calls, and showed how to convert them to SIP […]
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How to evaluate an echo cancellation algorithm?

  • On March 25, 2018
  When you encounter an echo problem in your application, network or devices it is obvious you need to introduce an echo canceller.  Your next step is to explore at least two possible locations for performing the echo cancellation: cancelling the echo on the client side or doing it on the server side. The decision […]
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Echo Cancellation with negative echo tail

  • On May 7, 2017
Background Echo path/tail is one of the most fundamental parameters when performing echo cancellation. In previous posts, we elaborated on the importance of echo tail and we also provided a Do It Yourself (DIY) method to calculate the echo tail. In most usage scenarios, the value of the echo tail will be a positive one […]
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Echo cancellation and public address systems

  • On January 13, 2017
Background When you hear the words echo or echo cancellation, you probably imagine a scenario in which two people are talking over the phone and one of them hears his/her echo. Indeed this is the most common scenario in which echo appears and echo cancellation mechanisms are being used.  In this post we would like […]
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Echo cancellation is now available for PJSIP

  • On December 12, 2016
Background PJSIP is an is a free and open source multimedia communication library. One of the most important components that influence the audio quality in VoIP communication solutions is the existence of a good echo cancellation.  SoliCall’s acoustic echo cancellation software is a powerful echo cancellation technology that is also flexible to support and tune […]
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Echo Cancellation on Android – synchronizing the input

  • On November 19, 2016
Background In this post we will discuss the challenge of synchronizing the audio that is given as the input to the echo cancellation software running on Android. This post is a continuation to a blog series we published on echo cancellation and specifically on the post that deals with importance of synchronization in echo cancellation. […]
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Echo Cancellation, Art or Science? Part II

  • On November 18, 2016
Background In the previous post on acoustic echo cancellation we discussed the importance and the challenge in handling of the echo path. In this post we will discuss a different aspect that echo cancellation algorithm must handle. It is not rare that users change the setting of their audio device during a call. For example […]
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Echo in Public Address systems – additional considerations

  • On January 16, 2016
Background This post is a continuation to our previous post on  AEC and Public Address systems. This post elaborates on additional considerations that should be reviewed when implementing and tuning acoustic echo cancellation software in PA systems. After analyzing relevant case studies, out of many important considerations, we have selected the below ones.
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Echo Cancellation and silence

  • On March 11, 2015
Background Following our previous post on synchronization, in this post we would like to cover a specific aspect of un-synchronized input which causes the speakers to play silence that is not monitored and therefore unknown to the AEC.
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