The echo cancellation can dramatically improve the quality of the calls and can work bi-directional. In addition, SoliCall offers a robust server-side and network echo cancellation that can handle a very long tail. As a result, phone calls contain, in addition to the speaker’s voice, acoustic echo and unwanted ambient noise like car horn, other people talking around you, wind noise, screaming kids, background music and keyboard-strokes. Even home-office can be noisy when your children are around. Phone calls are made from crowded and noisy environments, for example from call centers and from the road. The need for robust noise reduction and echo cancellation technologies is more important than ever. Now you can make your calls a pleasant experience. SoliCall is specializing in the fields of acoustic echo cancellation, noise reduction and noise suppression with the added value of identification of the speaker.
#Acoustic echo cancellation software software#
SoliCall is a leading provider of software products focused on improving sound quality in VoIP. The Bark Scale is a nonlinear audio frequency scale.Acoustic Echo Cancellation Software and Noise Reduction Solutions What we hear is almost by rule different from what is actually sounding, due to the peculiarities and limitations of our hearing. As soon as sound passes through the ears, it stops being a physical phenomena and becomes a matter of perception. Psychoacoustics is the scientific study of sound perception. So by distorting the signal in a pyscho-acoustic fashion, one mathematically de-correlates the signal but if done correctly will be less perceived as distortion to the ear. Essentially the ear is non-linear listening device. Pyscho-acoustic non-linear operators can be a good choice since the human ear hears sound on a non-linear Bark Scale. The downside of this is that the non-linear operators can cause too much audible distortion to the near end room listeners (since the speaker signals are now distorted). This has an effect of de-correlating the speaker signals which in turn allows the adaptive filters to converge more quickly with less misalignment. The usual solution to this problem is to perform a non-linear operation on each incoming signal. The individual adaptive filters can lock onto the same speaker signals producing an overall effect of slow convergence and high misalignment. The high correlation between speakers can produce non-unique “confusion” for the adaptive filters. The challenge with the SAEC is well documented and relates to the fact that the audio from each speaker is highly correlated (signals are similar) with the other speakers in the system since it is assumed all speaker audio outputs are coming from a common remote room. The actual echo cancellation requirements are not so straight forward. For the full-duplex stereophonic case, four (4) AECs are required. The number of acoustic echo cancellers (AECs) needed in a system containing N speakers and M microphones NM. On the surface the solution to the problem of cancelling multiple echoes seems relatively uncomplicated. In the SAEC case, each speaker will acoustically couple to each microphone in the system. Stereophonic acoustic echo cancellation is similar to monophonic (mono) AEC in that the echo in need of canceling is due to a speaker – microphone acoustic coupling. In such hands-free systems, stereophonic acoustic echo cancellers are absolutely necessary for full-duplex communication. Participants can more easily discern who is talking at the other end by means of the spatial aspect of the audio output. The stereophonic (Stereo) acoustic echo canceller (SAEC) software suppresses the echo returned to the transmission room to enable undisturbed communication between the rooms. In applications such as teleconferencing and hands-free telephony, stereophonic systems provide telepresence compared to monaural systems to users by enabling listeners to localize conference participants in meetings where multiple parties might be conversing at the same time.Ī high-end stereo teleconferencing system provides a more “natural” listening experience between conferees than monophonic systems. This disturbance, caused by echo, increases in severity with the propagation delay of the channel. In the case of stereophonic audio transmission, the acoustic echo cancellation problem is more difficult to solve because of the necessity to uniquely identify two acoustic paths. In order to provide a more realistic conversational experience, two-channel audio is necessary. Teleconferencing systems require the use of acoustic echo cancelers (AECs) to reduce echoes that result from coupling between the loudspeaker and microphone. Stereophonic (Stereo) acoustic echo cancelling (SAEC)