Silence suppression

Silence suppression

Silence suppression is achieved by recognizing the lack of speech through a speech processing mechanism called voice activity detection (VAD) which dynamically monitors background noise and sets a corresponding speech detection threshold. This technique is also known as speech activity detection (SAD). Silence suppression is a way to save bandwidth when conducting voice communications, or at least audio communications, over the Internet; it’s an advantage for businesses, especially companies that seem to specialize in Internet voice applications. Due to their networks and capacity not being clogged with useless data, the silence suppression technology requires a form of computer control timing protocol in which a specific operation begins upon receipt of an indication (signal) that the preceding operation has been completed, with the movement of data, a very easy task for the Internet to handle and the communication, between the two parties, without nearly the amount of bandwidth that would otherwise be taken up. Today, traditional phone lines cannot take advantage of any type of suppression technology, so this technology has developed along with Internet voice communications. Years ago, the entire channel through which the telecommunication was taking place was devoted to the conversation. That was not a problem because at that time the only function of the telecommunications system was to transmit voice data. The Internet transmits a wide variety of data, and with the greater demand for data transfer, the transmission speed can suffer. When the network slows down it becomes a problem for internet and voice communication which could lead to voice distortions and breaks and jumps between words, which could make effective communication all but impossible for the individuals trying to use it. Silence suppression can help that situation by effectively reducing the amount of bandwidth needed for voice calls to almost half of what would otherwise be required. What a silence suppression does can do is eliminate information by sending descriptions of the background noise, instead of sending the noise itself, a strategy that can certainly save money and equipment in the long run. The data being sent, and some sound can be heard by the user at the other end of the line. That sound, however, will only approximate the sounds a microphone is picking up at the other end of the conversation.
The WAN is the place where bandwidth is limited and the cost is high, so there is an incentive to apply VAD. The anticipated goal of saving as much as 50% of the WAN bandwidth, when using IP trunking, is very attractive. The first consideration is the number of simultaneous calls that will be carried over the IP trunk. Even though many calls will be combined on the back of the LAN switch, the total bandwidth consumed is far less than 10 Mbps. Therefore, there is no real value to applying VAD to the LAN environment.