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Time manipulation and its impact on echo cancellation

  • Posted by admin
  • On July 1, 2016
Background Time manipulation is a known technique in audio processing. It can be used to either compress the audio (resulting in speed-up) or expand the audio (resulting in slow-down). Usually this is done without altering the pitch and therefore without changing the fundamental signature of the voice.
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Echo cancellation is now available for PJSIP

  • Posted by admin
  • On May 15, 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 in Public Address systems – additional considerations

  • Posted by admin
  • On October 14, 2015
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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VoIP on Android – volume control

  • Posted by admin
  • On August 3, 2015
Background In our previous posts we covered few of the difficulties that Android VoIP developers are facing – for example the challenge in providing high quality echo cancellation. In addition to the echo cancellation, the variety of hardware platforms that are running Android also introduces a challenge in controlling the volume of the voice.  
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Echo Cancellation on Android and AudioRecord

  • Posted by admin
  • On May 22, 2015
Background When developing a VoIP application, most implementations use AudioRecord as the foundation class for capturing audio from the microphone.  Can this class be used to cancel echo as well ?  
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Echo Cancellation on Android – synchronizing the input

  • Posted by admin
  • On January 1, 2015
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 and public address systems

  • Posted by admin
  • On July 14, 2014
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, Art or Science? Part V

  • Posted by admin
  • On December 6, 2013
Background In the previous posts of this series we discussed the challenges of echo cancellation algorithms with respect to: 1. Echo path search . 2. Echo invalidation. 3. Howling effect. 4. Saturation. In this post we will discuss a common implementation issue we have seen many times – audio stream synchronization.
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Echo Cancellation, Art or Science? Part IV

  • Posted by admin
  • On April 10, 2013
Background In the previous posts of this series we discussed the challenges of echo cancellation algorithms to efficiently handle the echo path,  the complexity introduced by  echo invalidation and the howling effect. In this post we will discuss another important aspect with regards to echo cancellation called Saturation.
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Why Echo Cancellation for Android is a Difficult Task?

  • Posted by admin
  • On March 10, 2013
Background SoliCall offers different software solutions for audio quality improvements. One of the areas with an increasing demand is the need to solve echo issues with Android devices.  As discussed in few of our previous posts on  echo cancellation, in real-life conditions performing a good echo cancellation is a rather complex task. In addition, it […]
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