Why silence suppression is used

Accordingly, the measurement window size of 8 seconds used for FIGS. The power-frequency spectrum of FIG. In contrast, the power-frequency spectrum of FIG. Accordingly, the measurement window size of ms used for FIGS.

The power-frequency spectrums of FIGS. Further, the measurement window size of 20 ms used for FIGS. Also, these power-frequency spectrums illustrate the characteristic flat power spectrum of white noise and that music has the largest fluctuation.

In contrast, the differences in fluctuations for the power-frequency spectrums of FIGS. As a result, the power-frequency spectrums of FIGS.

Accordingly, a measurement window size of 20 ms is less effective as compared to measurement window sizes of 8 seconds and ms for determining whether the noise spectrum is constant or dynamic A measurement window size of ms is included in a preferred embodiment of the method Refining of the criteria for each determination should be based on multiple background noise samples.

The sub-band bandwidth used in the calculation should be determined by experimenting on differing background noise samples. More specifically, FIG. The test was conducted with a G.

The judged voice quality of the samples for music was significantly lower, by 0. For example, if the evaluation of the actual noise for the presence of white noise indicates the presence of such noise, then noise which is similar in sound to white noise may be added as the matching noise. The similarity in sound between the actual and matching noise may be increased by measuring the power-frequency spectrum, or other precisely definable characteristic of the actual noise on the channel, and adding matching noise having a power-frequency spectrum or such other precisely definable characteristic of the actual noise which is similar to that of the actual noise on the channel.

But even with these more sophisticated algorithms the addition of matching noise frequently sounds unnatural. The energy which is transmitted over the channel may be voice energy, the detection of which is provided by the step 14 of the method 10 of FIG. Alternative forms of energy other than or in addition to voice energy may be carried by the channel and detected by the method The method 10 may provide for the detection of such alternative forms of energy and for activation of the SS system if such alternative forms of energy have specific characteristics.

For example, the channel may carry energy which resembles the energy corresponding to the speech of persons talking to one another but such energy is not representative of persons talking to one another over the channel. Energy corresponding to the speech of persons talking to one another over the channel may be referred to as voice energy.

Energy which is not voice energy may nevertheless resemble voice energy, such as by being background noise which contains human speech. Such background noise may be from a television or people talking to one another in the presence of the one or more of the users of the channel. The ability to discriminate between these two forms of energy enables the SS system to be activated when the users of the channel stop talking even though energy corresponding to human speech, such as from a television, is being carried by the channel.

Consequently, the channel becomes available for transmission of voice energy from other channels. Such communication energy includes voice energy and other forms of energy, such as the energy which corresponds to a text message sent between two or more cellular phones.

The ability to discriminate between communication energy and other forms of energy enables the SS system to be suppressed when communication energy is being carried by the channel, even if such communication energy is not voice energy.

Consequently, the channel remains available for transmission of communication energy. Also, if communication energy is not being carried by the channel and the energy on the channel has other specific characteristics, then the SS system may be activated to make the channel available for transmission of communication energy from other channels, as indicated by the steps 16 , 18 in FIG.

For example, the nature of the energy may be indicated by the noise spectrum thereof such that the activation of the SS system depends upon whether the noise spectrum is constant or dynamic, as indicated by the steps 16 , 18 in FIG. It is possible for the activation of the SS system to depend upon other aspects of the nature of the energy detected on the channel. Additionally, the method 10 may provide for the detection of various types of energy on the channel.

For example, such detection may provide for the detection of the voice energy 14 , as shown in FIG. The method 10 may provide for the detection of types of energy other than voice or communication energy which also may be advantageously carried by the channel and therefore warrant the SS system to be suppressed. The entire disclosures of each of the following U.

While the embodiments herein have been described by reference to certain preferred embodiments, it should be understood that numerous changes could be made within the spirit and scope of the inventive concept described.

Accordingly, it is intended that these embodiments not be limited to the disclosed embodiments, but that it have the full scope permitted by the language of the following claims.

What is claimed is: 1. A method of controlling electrical communication, the method comprising: determining, using a voice energy sampling device, whether voice energy is not associated with a communication channel;.

The method according to claim 1 , further comprising determining the constancy criterion using a sum of squares associated with energy difference between adjacent sub-bands associated with a noise spectrum. The method according to claim 1 , wherein the communication energy comprises matching noise. The method according to claim 5 , wherein the matching noise comprises a constant frequency. The method according to claim 5 , wherein the matching noise comprises a constant decibel level.

A computer-readable storage device having instructions that, when executed by a processing device, cause the processing device to perform operations comprising: determining, using a voice energy sampling device, whether voice energy is not associated with a communication channel;. The computer-readable storage device according to claim 8 , wherein the operations further comprise determining the constancy criterion using a sum of squares associated with energy difference between adjacent sub-bands associated with a noise spectrum.

The computer-readable storage device according to claim 8 , wherein the communication energy comprises matching noise. The computer-readable storage device according to claim 8 , wherein the matching noise comprises a constant frequency. The computer-readable storage device according to claim 8 , wherein the matching noise comprises a constant decibel level. An apparatus that controls electrical communication, the apparatus comprising: a voice energy sampling device, the voice energy sampling device determining whether voice energy is not associated with a communication channel;.

The apparatus according to claim 15 , wherein the noise energy sampling device determines the constancy criterion using a sum of squares associated with energy difference between adjacent sub-bands associated with a noise spectrum. The apparatus according to claim 15 , wherein the communication energy comprises matching noise. The apparatus according to claim 15 , wherein the matching noise comprises a constant frequency.

USB2 en. CAC en. USB1 en. Audio signal evaluation program, audio signal evaluation apparatus, and audio signal evaluation method. CNB en. Voice determination device, voice determination method, and voice determination program. Method and apparatus for adaptively detecting a voice activity in an input audio signal.

WOA1 en. KRB1 en. System and method to distinguish sources in a multiple audio source environment. Awakening method, device and the electronic equipment of phonetic order execution function. USA en. USA1 en. System and method for suppressing silence in voice traffic over an asynchronous communication medium.

Method and apparatus for improved voice activity detection in a packet voice network. Synchronization of voice boundaries and their use by echo cancellers in a voice processing system. Method and system for implementing a low complexity spectrum estimation technique for comfort noise generation. Method and apparatus for mapping voice activity detection to a scheduled access media. Method of compensating for beamformer steering delay during handsfree speech recognition. Method, apparatus, and system for improving speech quality of voice-over-packets VOP systems.

Apparatus, method, and computer program for managing resources in a communication system. Method and system for implementing a gaussian white noise generator for real time speech synthesis applications.

Method and system for generating colored comfort noise in the absence of silence insertion description packets. CAA1 en. JPA en. CNC en. Refer to RFC See below. This feature allows you to configure T. The added negotiation will therefore reduce the call setup failure rate by increasing the content of the media offer.

In the event where the fallback scenario fails, the IMG is to allow the voice call to proceed, as if no negotiation had happened. This feature provides Fax packet redundancy to guard against network packet loss. Up to 3 levels are supported. Redundancy is applied to data and control T. This is only applicable to Relay Fax Mode. If this feature is enabled the IMG switches to another codec when you are in a modem call.

The codec that you switch to is specified in the Fax Bypass Codec field. For example, if you are using a low bit rate codec, such as G.