Unnecessary repetitions…repetitions…repetitions are disturbing and break the continuity of the call. When people have a discussion while they are physically close to each other, you hardly experience repetitions. But nowadays due to Covid-19 and social distancing many interactions happen via phone/video calls. In these calls repetitions are very common and they break continuity and significantly reduce the quality and efficiency of the calls. In this post we will cover the common causes for repetitions during phone calls and possible remedies.

Half-Duplex Echo Cancellation

Half-duplex echo cancellation are a common practice in telephony equipment and software. Practically this means that only one person can talk at any given point in time. In some scenarios, especially when delay is long and there is a difference in volume levels between the participants, the outcome of using half-duplex echo cancellation will be very annoying: as long as there is noise/voice from the louder side of the call, whenever the quieter participant tries to talk his/her voice will be blocked and he/she will have to repeat the same sentence again and again louder and louder until their voice is not blocked. The solution in this case depends on your control over the components and might range from replacing the half-duplex echo cancellation with a full-duplex echo cancellation, using an AGC to even the volume level of the parties, reduce the delay etc.

Malfunction Echo Cancellation

When any of the participants is using equipment or software that is not equipped with high quality echo cancellation, echo might be present. The result is that a person talking might hear himself/herself in a delay. In some cases the volume might increase in every repetition until a loud howling appears. A solution to this problem is to make sure echo is handled correctly in the calls. An advanced echo cancellation could be placed either at the end terminals/software or in a centralized server.

Ambient Noise

An ambient noise can be any unwanted sound that does not belong to the speaker. It can be a non-human sound, like car horn or dog barking, or a human voice like your spouse talking in the other room. As long as these noises are weak, they usually do not disturb the call but when they get louder they might cause the other party to request the speaker to repeat his last sentence. A remedy in this case is to use a high quality noise cancelling software that is cable of handling any type of noise. To learn more on this subject, we suggest reading the following post about the different types of noise that a noise cancelling app should handle.