“Send to the reference whatever you’re sending to the loudspeaker.” The AEC algorithm is “told” about audio coming out of the loudspeaker through a special input called the “reference.” Sending the right signal to the reference is critical. It essentially works by “telling” the microphone to ignore any sounds coming out of the loudspeaker. The goal of AEC is to remove this echo in the signal.
In addition, acoustic elements in the near-side room can introduce more echo into the sound picked up by the microphones, thus increasing the amount of echo in the output signal. Because of the inherent delays of transmitting audio from one geographical location to another, this transmitted signal is a delayed version of the original voice, thus sounding like an echo. This audio is picked up by microphones in the near-side room and then transmitted back to the far side. Without a firm grasp of how AEC functions, it’s hard to understand the various ways it can be applied.ĪEC is an audio processing effect found in Digital Signal Processors (DSPs) that are designed for audio conferencing, when there is a room with microphones and loudspeakers on the “near side” of a phone or online call as well as someone at the “far side.” The goal of AEC technology is to remove what’s referred to as “acoustic echo,” a byproduct of performing an audio call in a room with microphones and loudspeakers.Īcoustic echo occurs on a phone call when the far-side speech (from the distant person) is played over local loudspeakers in the near-side room. This is because there is a lot of abstract thinking involved, making it hard to explain what AEC actually does. It’s a standing joke within the AVL industry to refer to the work of AVL integrators as “the dark arts.” If that’s true, then Acoustic Echo Cancellation (or AEC) is a truly special kind of dark magic that the many use, but only the most talented of audio wizards truly understand.