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Video: What’s The Difference Between Masking and Suppression?

With DTMF, one of the frequently asked questions we get is to try to explain the differences and the different types of suppression/masking that’s surrounding the field today.

The two clearest use cases are masking and suppression. We designed our system using suppression, but I’ll explain the masking process first and then move on to why we chose suppression.


What is DTMF Masking?

Masking, in its own word, is to simply cover up something that is there. When looking at safety and information being passed into your contact centre; when that telephone call is connected to your systems, your network and your agents, to simply mask the data that’s being transposed on the line, from our perspective, is a bit of a concern. Because of all the regulations around PCI, talking about not having it present or storing it, obviously, if it’s being masked, it can be stored, or it can be heard by a human.


The Problem With DTMF Masking

However, to only mask means that you’ve paused the audio piece of that channel, often meaning that the agent can’t speak to the customer during that process, because the actual telephone call has been muted to mask the data. I’m sure you’ll understand, the downside with that is if I can add the mask, I can remove the mask, and essentially, the numbers are still present on the network and would need to be considered for de-scoping whether they were still in risk of scope or whether they were removed from risk. You would need to speak to your QSA to understand how that’s affected within your organisation.


The Benefits of Using DTMF Suppression

As for suppression, we came into this area, perhaps slightly differently. Our original systems are all self-serving, automated and time efficient. When we came to contact centre, we needed to replace that with the human piece. About 15% of our customers’ clients still required to talk to somebody when they’re making a payment. We wanted to make sure that we could let that agent handle that call and talk to the customer during all aspects of the call.

We also wanted to make sure that we weren’t allowing any of that sensitive data to, never mind get into your contact centre, but to even leave our data centre. We use dual clamping suppression. We clamp the DTMF when it hits our platform and use it to follow its function. But, then we clamp it on exit so that only the audio leaves our systems. That does mean that the agent and the customer can continue to talk throughout because there is no necessity to mute the call at all.


To find out how DTMF suppression can benefit your business please contact us. Call +44 (0) 1302 513 000 or email

Presented by Mark Kelly – Chief Commercial Officer (CCO) at Key IVR


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