We are frequency approached by new prospects with a simple request: could you help us cancel the noise in our audio? In order to address this question professionally, we first we need to understand what exactly stands behind the general word “noise” in the prospect’s request. Apparently there are many types of noise in audio and handling each one of them requires a different approach. In this post we will describe the most common types of noise and the recommended way to resolve each one of them.

Stationary noise

This type of noise refers mainly to constant ambient noise like constant street noise or constant racket in noisy locations like call centers. Another example is noise generated by an air condition. All these noises can be very disturbing and should be addressed by a noise-reduction algorithm that is capable of cancelling stationary noises.

Echo

Echo is the phenomena of a person hearing himself during a call. Sometimes the echo amplifies itself causing an ear deafening howling sound. This is maybe the most disturbing type of noise since a phone call cannot continue when echo is present. Although from scientific perspective echo is not considered as a pure ambient noise in practice echo is being described and perceived as noise and a very disturbing one. In order to remove the echo an echo cancellation software needs to be used. The echo cancellation software needs to extract from the audio that was captured by the microphone the sound that was played to the speakers. In addition, in most cases this echo cancellation software needs to be a very robust one as it needs to over-perform all other echo cancellation algorithms that failed cancelling the echo in the first place. The following page provides more details on echo cancellation.

Non-human sounds

This category includes all types of non-human sounds. For example this category may include sounds like music or car horn. In order to address this type of sounds the noise cancelling software needs to be able and identify these sounds as non-human and attenuate them.

Ambient human voice

This category is a very interesting one. It refers to human voice of other people talking around the primary speaker. The most typical scenario for this type of noise is a call center environment where you have agents sitting next to each other talking over the phone with different customers. When a customer is talking with an agent he/she can hear in the background the voice of other agents talking. In many cases the customer can understand what is being said by the other agent in the background. For example the customer may hear a commercial offer that is provided by the other agent in the background to another customer. In order to remove these background human voices the noise reduction software need to have the capability to identify the source of each human voice and based on its location decide if it is an ambient voice or it belongs to the primary speaker. For more information take a look at the Noise Firewall solution.

Conclusion

Now we know that the word “noise” is actually a general term that includes many categories that each one of them needs to be addressed in a different way. In few cases we see only one type of noise in an audio stream but it is more common to find few types of noises combined in a single audio stream and therefore a combination of technologies needs to be used to cancel them all. Therefore, if you experience noise in your calls, try to identify their nature and select a field proven noise cancelling software that can address all of them. For more information and assistance please contact us.