Fact Checked

What Is a Dialogic Card?

Lakshmi Sandhana
Lakshmi Sandhana

A dialogic card acts as an interface between analog telephone signals and the peripheral component interconnect bus, or PCI bus, found in computers. Buses within a computer act as channels connecting different components. The dialogic card handles information from analog phone lines and are used in applications such as voice messaging, notification systems, auto dialers, and voice mail. They are also used for interactive voice response, automatic call distribution, and voice or audio response systems. Used in many voice recording products, dialogic cards are produced in both digital and analog configurations depending on the way they are utilized.

Allowing high-density applications, dialogic cards are mostly used in automated telephone systems with services such as predictive dialing and conferencing. There are cards that can handle a number of phone calls simultaneously. A dialogic card can even route each call to the correct representative. The core function of a dialogic card is to integrate computers with telephones, enabling a wide variety of functions. The internal distributed bus switching allows rerouting of both inbound and outbound calls.

Dialogic cards can detect the touch tones of a telephone.
Dialogic cards can detect the touch tones of a telephone.

Voice decoding and encoding, retrieving caller ID numbers, and making and answering calls are all made possible through a dialogic card. It can detect the touch tones dialed, record sounds from the phone line, and identify when the connection has been severed. Most of the cards can handle many analog lines and have protection circuitry on board that makes them very reliable. Certain signaling functions, like current detection, can not only be monitored but also controlled through the computer with the help of a dialogic card. It's also possible to configure multiple boards within a single chassis and expand the number of analog ports easily if necessary.

Earlier applications for dialogic cards were written with telephony application programming interfaces or APIs, like Dialogic R4, GlobalCall, and ECTF S.100. ActiveX controls like visual voice and Java-based APIs, including API and JTAPI, were also used to create telephony applications. They all, however, had numerous issues. The Java-based APIs are no longer utilized, and the ECTF S.100 is used very rarely. Other proprietary scripting languages have also been abandoned over time.

All these APIs were constrained to very specific operating systems and were not widely adopted as standards. They all fell into disuse as more modern, web-based standards evolved. Two widely used telephony standards that became popular over time were VoiceXML and CCXML. They have the added advantage of being based on the ubiquitous XML and HTTP, making them easier-to-use web-based technologies.

You might also Like

Discussion Comments


Does anyone know where or if I can get hold of some Dialogic Cards for our voice recording system? It is old and is not behaving well, but we can't afford a new system yet. It is referred to by a number of names: 'Talking Computer' 'Audiowatch' and 'Superdesk.' It is version 9.07.02. Any help would be appreciated. --Darl.


@SkyWhisperer - What’s cool is that the technology has now been made accessible to the public, if you are a programmer that is.

The article mentions APIs, which are basically libraries that will let a programmer access the technology and create their own telephony applications.

You can create your own voice recognition application if you want, like something that would operate common computer software applications with only your voice to guide them.

I’ve played with similar commands in other languages that did comparable things. I have been able to create simple text to speech programs and also some very basic voice recognition software too.


@David09 - I still prefer the live customer service representative, but I agree that the telephony applications have been real time savers in reducing the customer service workload.

At my job I do some technical support, and there are days when I wish a computer would take over when I answer the phone calls. I guess I don’t have the patience of that pleasant sounding female voice you described.


@everetra - I completely agree. Think about what these things have done in terms of reducing the customer service workload too.

Awhile back my cable modem was down and I called in to get it fixed. Rather than speak with a live customer service representative (which I would have preferred at the time) I was directed to a telephony system to help diagnose and troubleshoot the issue.

The computer used a pleasant sounding female voice, and step by step “she” (or it) guided me through the whole process. At first, I thought she would only tell me to reset my modem or reboot.

Instead, however, she was able to perform progressively more complex tasks, like viewing my computer on the network and doing a remote reset of the modem from the cable company’s end.

My problem was resolved without ever having to speak with a live person. I was impressed.


I can’t believe how far we’ve come with telephony applications. In the early days if I called into a customer service system I was given a menu of options that I had to punch from the telephone number pad.

Nowadays I can speak into the phone in response to the telephony system’s questions, and in most cases it can understand what I say. Of course, these are simple one word responses like “yes” or “no,” or in some cases it wants me to recite my account number. So it’s not difficult in that sense, but years ago that technology would have been nearly impossible.

It’s all made possible by the dialogic card and the world of telephony.

Post your comments
Forgot password?
    • Dialogic cards can detect the touch tones of a telephone.
      Dialogic cards can detect the touch tones of a telephone.