Category: History

  • “For faster service, press 1”

    by Glen Taylor

    We all experience them; those annoying announcements at the beginning of many calls answered by some form of technology.  Perhaps the most common today is the obviously false announcement to “Please pay attention as our menu options have recently changed.”  Those of us in the IVR community know that menu options SELDOM change.  But, do you recall the “For faster service, press 1” announcement.  Younger readers may have never heard it, but during the 1990s and 2000s, this was a common occurrence.  Although not all of the announcements may have a good reason behind them, this announcement did.

    Before explaining why you were encouraged to place this announcement at the start of an IVR answered call, a little background is necessary.  The use of this message, or the lack thereof led to an interesting detective story.  But, before it will make sense, some background is required. Again, the younger reader may find all of this alien since modern telephony has passed this by more than a decade or so ago.  When Bell invented the telephone, the devices were simply “electrical” devices.  A phone was at one end of a pair of copper wires and a “central office” was at the other.  As technology advanced, the “central office” end became a switching system and it might have been a telephone company’s central office switch or a company’s private branch exchange (PBX).  When a caller lifted the phone’s handset to “dial,” this closed an electrical switch.  The handset sat in a cradle and depressed a switch (the “switch hook”) which “opened” the electrical circuit.  When the handset was lifted, spring lifted the switch hook and the electrical circuit became “closed.” This completed the electrical circuit, and the central office or PBX switch end recognized this by putting dial tone on the line.  The caller then “signaled” the switch the number that was being called by sending a string of encoded numbers.  The only means of “signaling” was to effectively hang up and lift the receiver a number of times in rapid succession.  This would generate a string of on-off pulses in the phone connection.  Since people can’t reliably do this signaling manually, the rotary dial was invented.  When the caller “dialed” a number such as the number 4, the dial would turn the phone connection off and on rapidly four times.  This “decadic” or “dial pulse” method was standard for decades.

    As technology progressed and electronic technology became inexpensive enough to incorporate into telephone sets, a signaling system based on audible tones was invented.  Each of the phone digits was represented by a pair of very precise tones emitted for a prescribed duration.  Because there were two tones of different frequencies for each digit, the scheme was called dual-tone multifrequency or DTMF. However, it was more colloquially known as touch tones because you “touched” a button on the telephone corresponding to the digit and the “tone” was produced. 

    The invention of DTMF made possible a number of new things, but it was initially more expensive on the phone company end as well as in the telephones themselves.  Since the phone company, primarily AT&T as the Bell System, owned the switches and the telephones, it bore the cost of replacing older switches and phones with newer ones that worked with DTMF.  DTMF phone service was priced higher than dial pulse service.  The costs rapidly came down and even reversed – it cost the phone company more to provide dial pulse service than touch tone service – but the price difference remained.  Phones became more sophisticated.  Rotary dials disappeared in favor of phones that only had the push buttons that were the hallmark of touch tone service.  Ironically, most phones had to have a setting to indicate whether pushing the number 4 would send the DTMF signal for 4 or the four decadic dial pulses for four.  Many people now owned their own phones (another major change for AT&T) but they might still be paying for dial pulse service (recall, it cost less) even though their phone was capable of both.

    Dial pulse signaling only worked reliably between the phone and the switch it was connected to.  Yes, someone on a completed call could “press a digit” and dial pulses would be generated, but only the switch directly connected to that phone was capable of responding to the digit.  Once a call was completed, the switch would ignore dial pulses.  They were simply “noisy interruptions” to the connected voice path.  Only when the caller “hung up” long enough would the switch decide that the call was finished.  If a caller pulsed digits during a call, clicking might be heard by the party on the other end but no reliable signaling passed from the caller to the listener.  If the caller pressed a touch tone digit during a call, the listener at the other end would get a clear DTMF signal.  The human ear can’t reliably interpret DTMF digits, but an IVR application can.  Thus, most IVR applications in the 1980s onward played recorded messages to a caller and prompted the caller to send DTMF digits in return.  This made for a powerful and reliable form of interaction.

    Let’s return to that “For faster service, press 1” announcement.  In the 1990s and early 2000s, there was a substantial mixture of consumer phone users having dial pulse service and touch tone service.  Most would have phones that actually had buttons to send digits, but their phone would have been “set” to either generate dial pulses or generate DTMF digits.  When a caller reached an IVR application, the application would typically play some prompt like “Please enter your account number,” and the caller would (hopefully) faithfully push the buttons corresponding to the account number.  At this point, one of two things would happen.  If the phone sent touch tones, the application could proceed appropriately.  If the phone sent dial pulses, the IVR would “hear” some form of clicking but it would not be able to reliably detect what digits were intended.  The result was usually an impasse that could only be resolved by transferring the caller to an agent who could conduct the transaction through a conversation.

    Since the IVR platforms of that day required touch tone input (reliable automatic speech recognition was emerging but it would not be accurate enough for a while and it was significantly more expensive to use), some means was needed to quickly screen out dial pulse callers and send them to agents.  There was no need to “waste time” (either the caller’s or the IVR’s) trying to interact with a dial pulse caller.  Better to send them immediately to an agent.  Thus, the “For faster service, press 1” announcement was born.  This became the recommended initial prompt for essentially all IVR applications of the time.  Dial pulse callers might send a “click” but the IVR would receive no DTMF digit.  It would recognize this condition as a caller who didn’t respond or a dial pulse caller and immediately initiate a transfer.  It usually didn’t really require a digit 1, any digit would do but 1 was the “cleanest” dial pulse digit.

    Unintended Consequences of Not Using the “For faster …” Announcement

    Since Conversant was a programmable device and the applications it ran were up to the user, and specifically the people who created the user’s applications, Conversant could not force the use of a particular announcement.  However, it was a strong recommendation.

    I became involved as a “subject matter expert” when AT&T’s legal team was preparing its brief in defense of a potential lawsuit.  Our customer, Citibank, had deployed Conversant equipment in its credit card division and card holders could call into Conversant applications to do various self-service tasks.  Initially, Citibank took our recommendation.  Each call began with the “For faster service, press 1” prompt with dial pulse callers shunted to agents immediately.  If the caller responded with a DTMF digit, the application proceeded to ask the caller to dial in his or her credit card number.  The rest of the application proceeded from that point. 

    Citibank received a high volume of calls.  The cost of servicing these calls, even with an IVR application, was higher the longer the calls lasted (number of calls times the duration of a call times the cost per unit of time equals the total handling cost.  This could be a big number.)  Citibank decided that it could reduce its costs significantly by merely skipping that initial prompt.  After all, it takes a few seconds to play the prompt, for the caller to hear, and for the caller to respond.  Why waste all that time on an interaction that didn’t advance the purpose of the call?  Why not just immediately ask for the account number?  That’s what Citibank did.  They eliminated that initial prompt. 

    Citibank’s credit cards were Mastercards.  All Mastercards begin with the digit 5 followed by a fixed set of digits that identifies the bank, in this case Citibank.  The rest of the 14 or so digits represent the individual card holder.  It turned out that Citibank had many customers living in a suburb of Chicago.  The central office switch serving this community was an older 1A ESS switch so all or nearly all of the customers in that community still used dial pulse service.  Once Citibank eliminated the screening prompt and prompted directly for the card number, all of the callers from that community would pulse “5 – digit – digit – etc.” corresponding to their card numbers.  Every one of those cards had exactly the same first 8 digits.  This had an unintended consequence that got Citibank sued.

    It turned out that the 1A ESS serving this community worked fine with dial pulses used to initiate calls.  That’s to be expected.  However, if a caller began to pulse digits DURING a call, the switch sees that as the caller rapidly hanging up and then going “off hook” repeatedly.  In most cases, the switch would ignore a few temporary interruptions in a call and keep it connected.  In this case, the switch interpreted the digit “5” as the caller hanging up.  Worse still, once that 5 digit was done, the caller was back “off hook” as if he or she wished to place a new phone call.  The central office switch then applied dial tone and received the next seven dial pulse digits as a new phone call.  It so happened that those seven digits corresponded to the phone number of an actual telephone subscriber.  The woman who owned that phone number was not amused to receive dozens of calls a day and at all hours of the night from Citibank card callers who were trying to access Citibank’s automated IVR system.  She sued Citibank!

    Citibank’s response was to have its legal team try to add AT&T to the suit and make us the “responsible” party since it was “AT&T’s IVR equipment” that was failing.  Needless to say, the detective work required to figure out what was happening (that I just described) was an “interesting” exercise.  Our lawyers pointed out to Citibank and the court that we had recommended they use that “screening” question.  When they had, it worked as expected and this problem did not and would not occur.  By ignoring our advice and unilaterally removing the prompt, they had brought this upon themselves.  It was, admittedly, a strange edge condition of how the phone network worked, but AT&T was not to blame either via its Conversant product or its former local telco’s regulated telephone services (in that Chicago suburb). 

    My involvement was done at that point.  I don’t know whether Citibank settled with the litigant and whether they went back to using the initial prompt, although I suspect that both happened.

  • Memories of CVIS

    by Michael Womeldorph

    Quick CVIS background:  I started w/ Bell Labs CVIS in 1989 as a member of the Tier 4 Support team.  The support team was arguably the folks closest to the customers and use cases as we supported most trials and live systems.  A couple years later, AT&T relocated me to Denver to help bring up the domestic technical assistance center (TAC) then later the international support team (ITAC) for CVIS and Contact Center solutions.  I personally enjoyed the international support the most as I got to travel globally on AT&T’s expense and learned a ton about how our solutions were viewed/used in far off places (I ended up in international roles for the next 20 years).  So just a couple quick international stories about introducing CVIS into other cultures.

    Speech Recognition in the UK:   We started introducing CVIS speech rec after our solution in the US was working fairly flawlessly (e.g., recognition at 90%+).  The UK seemed like a good market for us, since we had the English version working well.  When we first started testing in the lab the accuracy was pretty good (around 85% or so) so we ended up doing a live trial.  After starting the live trial, the initial results were quite bad (less than 50% accuracy).  It was puzzling as to why the live trial was so poor, but since the system captured and saved the input from the customers, we pulled them down and started listening to the inputs.  Funnily enough, upon hearing the inputs, it was clear what the problem was; when prompted to ‘say “one” for X, “two” for Y’ etc.,  the Brits where swearing at the prompts (e.g., ‘*&%#, “one”).  In general, our British friends are much more comfortable swearing in everyday conversations than we are (I learned this first-hand a few years later as I took a 2 year assignment in the UK).  At any rate, our genius R&D team came up with the perfect solution; they built speech models for the most commonly used swear words, and changed the script to disregard any of the swear words and to look for the next word.   The accuracy of the trial immediately moved up to the +80% range!  

    Spanish Text-to-Speech and Voice Prompts:  When we developed the initial systems into Spanish, someone from the design team and I reached our to our team in Mexico to demonstrate the solutions and see if we could start lining up some trials.  We got to the office in Mexico City, set up the demo system, and got some of the key staff in the office together for a demonstration.  The reaction was immediately and universally both  heartening and disheartening:  “That’s really cool!  But you can never sell that here”.   When we asked the obvious ‘why?’, they explained to us that the demo solution used Castilian Spanish, which would never be acceptable in Latin America.  Kind of like us trying to use a NYC or southern accent in the rest of the US (Audrey Audix had a beautiful Ohio accent that is acceptable throughout the US).  So our key learning from the trip was that for Latin America, we needed to use voice talent from Colombia, which is acceptable throughout the region, and definitely not Castilian (which would be like trying to use BBC English in Macon Georgia)…

  • Necessity is the Mother of …

    by Dave Schinke

    A first IVR customer was successful, and the Conversant Model 80 IVR product was being marketed to different customers.  A time came when there were several “big” customers, and the number of manufactured machines needed to increase to about 30 to satisfy these sales. Soon, the Western Electric factory engineers were finding that when a cabinet was constructed, it was taking 3 or 4 days to “qualify” a cabinet:  test it, clear any discovered faults, and make it ready to be shipped.

    “We are getting killed on test time.  Is there anything Bell Labs could do to help us with the problem?”   This phrase and question began to circulate in the Dept. and Bob Perdue, my current supervisor, shared the query with a number of us. I’m sure the “hardware” development people were engaged, and what could the “software” folks possibly do to affect the problem? 

    Let me pause the narrative and describe in more detail some of the physical features of the Model 80 equipment cabinet. 

    • The circuit boards were multi-layer “printed” circuit boards, maybe 10” wide by 14” long. They generally had factory level electrical tests that could assure that the individual board was good when manufactured.  Also, the firmware on the board usually had internal self-diagnostics that would operate on each power-up and determine the board was operational, or set a software error condition for replacement.
    • The circuit boards slid into vertical slots on a shelf with guide rails, front retaining clips, and a rear connector would engage with a double row of plated steel pins that were embedded in a “backplane” board.  Each pin went through the board and also protruded out the rear of the “backplane.”  Imagine looking at rows of shiny “porcupine” quills sticking out from front and rear.
    • The interconnection wiring on the rear of the backplane was done with “wire-wrapping” tools that stripped an end of wire, wrapped it on a rear pin, then manually pulled the wire to the desired pin, and stripped, wrapped and cut the other end.  This was a manual, human operation and subject to error.  Further, a “bent” pin on the front side could fail to engage the inserted circuit board, producing another fault.

    The Model 80 software could interact with circuit boards, run internal diagnostics, etc, and fairly quickly locate circuit boards that had internal faults.  But this “backplane” needed visual inspection, which is a tedious process dealing with the “porcupine” mass of pins. And the backplane carried the audible voice signal for 48 channels.

    There is an old saying “Necessity is the Mother of Invention”.  We all kind of scratched around with the problem, but there was no immediately obvious solution that would reduce the testing time.

    “Hey, Roy”, I said as I plunked myself down in a chair in Roy Grubbe’s office.

    “I want a machine that will test itself” referring to the Model 80 machine. 

    “We can make tones, and we can hear tones.  Is there a way to test the voice paths of the machine using its own abilities?”  was my basic query to a fellow staffer.

    Roy wasn’t immediately dismissive of this, as many of the things I proposed had previously been.  Roy thought if we could put a “loop back” cable on the cabinet rear phone connector, we could use a tone generator of one shelf to send tones into the detection circuits of the other shelf. We started examining the wiring diagrams to figure out what voice channels could be covered, if any would be missed, etc.  Each Model 80 had two active shelves of equipment to service 48 phone lines.  Each active shelf had two standard 48 pin telephone connectors. (note: two wires made up a standard phone line.)   By some quirk of the circuit pack arrangement that I have forgotten, we needed two sets of cables to join 2 top connectors to 2 bottom connectors.  One pair of cables joined the connectors in a “parallel” arrangement, and the other joined in a “crossed” arrangement.  We did come out with a tentative wiring diagram for the cables that would provide full coverage of the voice paths inside the machine.

    Roy started thinking about the test software that would run tests, locate problems and print out errors to point to the backplane locations with faults.  Roy was a remarkable developer.  He worked as quickly as he thought.  It all just flowed into executable code. I explained to our Western Electric engineer what we were trying to do, but that we didn’t have the resources to make the cables. He immediately said, “Just get me the diagrams, and I will have the wiring shop make them quick like a bunny.”  And he did get them made quickly.

    This idea of a self-testing machine had become a physical reality. Roy’s software worked and was debugged in rapid fashion.  I started working on the factory floor for several days with the Western Electric test people to get the tests working in practice, get their feedback, and to be the go-between to Roy for software needs, fixes, etc.   I don’t remember how quickly the test procedure stabilized, but it wasn’t very long. 

    The self-testing software reduced the time to qualify a machine from several days to less than one day, and significantly boosted the Model 80 production rate.

    Author’s footnote:  This story was constructed without the use of Artificial Intelligence, just my fingers on a keyboard.  All errors and omissions are mine and mine alone.