Why do Phones echo?
Any person who possesses a cell phone might have experienced for at least once the echoing of one’s own voice in the phone. This will be heard by the person whose voice was echoed. The individual on the other side will not hear anything. If the echo is heard by you when you are speaking on phone, it is better to hang up that connection first. Then you can redial the same number and speak to them. The phone connection being weaker, will not allow the phone line to be clear. If the phone line is not clear then we can hear echo.
If echo is heard properly we can identify the actual cause of this echo as the way it is presented in the phone. Echo is of various types like network echo, acoustic echo, side-tone echo and local area network echo. The echoing occurred while making a call using PSTN or TDM connection is called network echo. When the caller hears the echo of the person on the others side and when the call was made from an SIP phone or from outside office, it would be network echo. If you use a speaker phone or your office room has a high roof and a flat surface, the echo can be heard due to the reflection of voice by the flat surfaces. Then this type of echo is called as acoustic echo. If the echo is heard when any person keeps the phone speaker near his own receiver, then the call in the connection is said to be active. This was found to be present in Astra phones. If you can hear your own voice into your ear then it is called as side-tone echo. When the delivery of packets was done successfully within the LAN connection, an echo is heard. This type of echo is called as LAN echo. If you can hear echoing of your own voice as well as that of other voices then it is called as LAN type echo.