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Interactive Voice Response (IVR)

Musaab M. JasimYildiz university

Computer department

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Outline Introduction and Brief history. IVR general using and applications. IVR definition , deployment and Ivr-system . IVR techniques :

I. DTMF IVR .

II. Speech recognition IVR.

IVR phonetic speech recognition model . Speech recognition system engine . Speech recognition IVR types . Advantage and Disadvantage of IVR .

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Introduction andBrief History

Introduction and Brief History

Introduction

When a customer calls in a company. Call is answered, not by conventional receptionist , but by an electronic receptionist (an automatic attendant).

This e-receptionist directs you towards getting your query resolved. But , Who is this electronic receptionist? This Electronic Receptionist is IVR ( Interactive Voice Response )

And this what will talk about it in this presentation .

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Introduction and Brief History

Brief History

Between the 1961 and the early 1970s a big breakthrough in a speech technology and telephone service are occurred when the American Bell Telephone Company unveiled of a developed Telephone System with a new tone dialing methodology that could dial area codes using DTMF technology , and when a link between speech and mathematics is appeared by Leonard E. Baum, and Lloyd R. Welch who developed an approach to recognition based on a statistical concept called the Hidden Markov Model. The blueprint for IVR was born as Voice Response Systems are based on DSP technology with limited and small vocabularies .

Early 1980s , Leon Ferber realized that hard drive technology has finally reached a cost effective price point . this make the system could store digitized speech on disk, play the appropriate spoken message, and process the human's DTMF response.

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Brief History.

In the late 1990s , while the call centers began to switch to multimedia ,

companies started to utilize the computer telephony integration (CTI) to

create a vital IVR system which acts as agent which collected customer

data to enable intelligent routing decisions. 

Recently , With improvements in technology, systems could use speaker-

independent voice recognition of a limited vocabulary instead of requiring

the person to use DTMF signaling._______________________________________________________________________

And below some examples and details about using the IVR in turkey

First IVR System / 1991 ITD (Information Technology Division) successfully implemented the first interactive voice response systems in Turkey at Pamukbank*, Yapý Kredi Bank and Akbank.

First Digital IVR / 1992ITD made the implementation of the first biggest digital IVR system in Turkey.

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Brief History.

First National Switch Center (BKM) / 1993ITD has important contributions at the formation of the first and only transaction switching system project of Turkey.

First Internet Integrated Call Center / 1998ITD began to work on the first internet integrated call center project at Garanti Bank and successfully made the implementation in February '99.

First Speech Recognition System / 2000ITD launched Turkey’s First Speech-Enabled Call Automation System in July 2001 with Global Menkul Deðerler.

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IVR general using andapplications

IVR general using.IVRS are used in many aspects in life but the general using of it in (telephone system & World Wide Web ) as shown in these points below I.It used to Front-End a call center operation , to identify caller needs and execute it and sometimes after (Security detection task) by comparing the information obtained from the caller such as (caller account , pre-recorder information ) with Caller ID data.

II.It used with Automatic Call Distributor (ACD) to play announcements and received the inputs of the customers request .

III.It used in Voice Email to ask the customer if he want remove , read , edit and hear the message .

IV.Accesses or stores information to and from the back-end host, database or the Internet by using applications used for Web pages such as VoiceXML , CCXML and SSML .

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IVR applications.IVR finds its application across the industries in many ways. As shoe below :1.Auto Receptionist: it means serving the call of customers.

2.IVRS telephonic alerts: used to call the customers or employees or other stakeholders to provide them with some useful information .

3.Customer Care Automation .

1.IVRS inventory control : used to maintained the customer information over the telephone line .

2.IVRS reservations: the speech-enabled IVRS is convenient way to book tickets or spaces.

nIVRS Campaigning: such as using it for Social Campaigning like polio vaccinations .

nIVRS Status Information .10

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IVR definition , deploymentand Ivr-system

IVR definition , deployment and system IVR detention

It is a technology that allows a computer to interact with humans through the

use of (1)DTMF (tones input via keypad) Or (2)Voice , and enables the

customer to retrieve information from a database, enter information into a

database, or both , By following a series of simple interactions in the form of

a conversation called the " IVR dialogue " . Thus , it allows to the customer

to efficiently exchange information , reduces " Written Processing ", cost

and improve the customer experience.

IVR general deploymentWe can find the IVRS as :

I. Equipment installed on the customer premises .

II. Equipment installed in the PSTN (public switched telephone network) .

III. Application service provider (ASP) / hosted IVR .

IV. Virtual Hosted IVR12

IVR definition , deployment and system Interactive Voice Response System (IVRS)

the system which provides a self-service for customers by guiding and enabling them access to the Automated departments such as (Automated bank) , get Services such as (airline schedules or movies times ) and Information that they need such as (account information). By using technologies that allow a computer to automatically detects voice and touch tones and analysis it then react to customer request by providing the answers for their queries via pre-recorded messages or dynamically generated audio , thus cut down customer service costs .

IVRS components :I. audio equipment .

II. DTMF tone recognizer .

III. language modeling technology .

IV. IVR's software application .

V. database.

VI. a supporting infrastructure

VII. sometimes , a text to speech converter is also used.13

IVR definition , deployment and system IVRS architecture block diagram

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IVR definition , deployment and systemWhere the Modern IVR systems enable users to interact through a computer system via two interfaces : I.Interactive Voice Response System Interface (IVRS-I) .

II.Interactive Web-Based System Response interface ( IWR-I ).

IVRS example

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IVR Techniques

IVR Techniques There are three techniques are used by IVR to interpret the customer's

response to prompts:- I. DTMF decoding .

II. Speech recognition .

III. Sometimes using TTS(Text-To-Speech) to speak complex and dynamic information such as E-mail , news reports or weather information .

I. DTMF decoding technique

IVR with " Dual-tone multi-frequency signaling" approach is a technology that allows computer to detect DTMF (Dual-tone multi-frequency) keypad inputs which are generated by customer and trying to meet his request according to input.

(DTMF) is an international signaling standard for telephone digits. These signals are used in touch-tone telephone call signaling as well as many other areas such as (interactive control applications, telephone banking and pager systems).

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IVR Techniques A DTMF signal consists of two superimposed sinusoidal waveforms whose

frequencies are chosen from a set of eight standardized frequencies.

Low group (Hz): 697, 770, 852, 941

High group (Hz): 1209, 1336, 1477, 1633

And these frequencies detect by detector part of early DTMF systems consisted of analog implemented bandpass filter-banks, which were tuned to the eight standard frequencies.

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IVR Techniques

using for only the Public payphones that accept credit cards use these additional codes to send the information from the magnetic strip.

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DTMF keypad

- The DTMF telephone keypad is laid out in a 4×4 matrix of push buttons in which each row represents the low frequency component and each column represents the high frequency component of the DTMF signal. Pressing a key sends a combination of the row and column frequencies.

- But in the recent years , a group of keys for menu selection: A, B, C and D were dropped from most phones , and still

IVR Techniques Keypad tonesIn the table below the example of the tones of DTMF keypad

So for dialing , we will press many digits and that will create the dialing tone which be superposition of many Low and High frequencies , as show in the next slide:

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DTMF keypad frequencies (with sound clips)

Frequencies groups 1209 Hz 1336 Hz 1477 Hz 1633 Hz

697 Hz 1 2 3 A

770 Hz 4 5 6 B

852 Hz 7 8 9 C

941 Hz * 0 # D

Dialing ToneDialing Tone

IVR Techniques For example

the key 1 produces a superposition of the tone with 697(Hz) and the tone 1209(Hz). Initial pushbutton designs employed levers, so that each button activated two contacts. The tones are decoded by the switching center to determine the keys pressed by the user.

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1209 Hz on 697 Hz to make the 1 tone

IVR TechniquesII. Speech Recognition technique

It is a technology that allows to taking the commands and execute functions

using natural voice signal instead of pressing the numbers on telephone or

machine .

Where the words spoken by the customer are chopped into smaller pieces and

compared with the words that are already stored in the database, and execute

the command which is most similar to the one stored in the database.

This enables customers to avoid complex DTMF commands. Also, unlike touch-

tone IVR/IVRS, it does not restrict the input to ten digits or keys. So, it is

allowing customers to interact more naturally. 

Until now speech based IVRS is able to except few discrete numbers and

alphabets, instead of free flowing voice. But, speech-enabled IVRS allows user

to speak normal sentence rather to take unusual pauses. Also, these systems

allow voice signals of all frequencies rather accepting only single or very few

frequencies, thus making it speaker independent.

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IVR TechniquesIn phone system , This IVRS is proved to be a good substitute to the “receptionist attending” the phone calls. You can handle multiple calls at a time using this technology. Thus reducing the labor cost and providing better customer service. This works best when combined with a touch tone IVRS system. It is best suited for applications where directed responses are needed, like where you are giving option to the caller to answer in either YES or NO, and where the inputs are limited. 

And to ensure high efficiency, these systems use Artificial Intelligence (AI). (AI) takes care of (1)dialogues (2)grammar (3) responses, in order to understand the customer's requirement. Also, wave editors are used to improve the quality of voice.

The programming languages which used to develop speech recognition IVRS are Voice XML & Speech Application Language Tags .

But what is the speech recognition and speech recognition system engine

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IVR Techniques

Speech Recognition (SR)

It is the ability of a machine or program to identify words and phrases in spoken

language and convert them to a machine-readable format , it also known as

"Automatic Speech Recognition (ASR)" .

Most IVR system uses one or more of four categories Speech Recognition

methodologies in the conversion process.

1.Template Matching .

2.Acoustic-Phonetic Recognition .

3.Hidden Markov Model .

4.Neural networks .

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IVR Techniques

1- Template MatchingTemplate matching is considered the oldest and least effective method. It is the primary technology applied to speaker verification, (Moore, 1982).It is a form of pattern recognition.Each word or phrase in an application is stored as a template. The user input is also arranged into templates at the word level and the best match with a system template is found.

2- Acoustic-Phonetic Recognition Acoustic-phonetic recognition is a function at the phoneme level.Where It is an attractive approach to speech as it limits the number of representations that must be stored. It involves three steps,

I. Feature Extraction.

II. Segmentation and Labelling.

III. phoneme-Level recognition.

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IVR Techniques3-Hidden Markov ModelThe Hidden Markov Model (HMM) is a popular statistical tool for modelling a wide range of time series data.The basic principle here is to characterize words into probabilistic models wherein the various phonemes which contribute to the word represent the states of the HMM while the transition probabilities would be the probability of the next phoneme being uttered.Where models for the words which are part of the vocabulary are created in the training phase .in the recognition phase when the user utters a word it is split up into phonemes as done before and its HMM is created.After the utterance of a particular phoneme, the most probable phoneme to follow is found from the models which had been created by comparing it with the newly formed model.This chain from one phoneme to another continues and finally at some point we have the most probable word out of the stored words which the user would have uttered .thus recognition is brought about in a finite vocabulary system.Stochastic processing using Hidden Markov Models is accurate, flexible, and capable of being fully automated .

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IVR Techniques

4- Neural networksit is type of an artificial neural network which is a computer program, which attempt to emulate the biological functions of the Human brain for recognition the speech .it assumes that the speech recognition systems could learn a knowledge the speech automatically and comprehends the meaning then response as the human brain .this system consists of a huge number od accurate processors that perform reliable speech processing .until now , it is not actually wide apply in the IVR system .

Recent , the most of Speech Recognition IVRS uses a " Phonetic Speech Recognition model " based on Acoustic-Phonetic Recognition Idea.

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HMM diagram The state above the dash line is

the hidden states . The O is the observation

sequence. A is the state transition

probability. B is the observation matrix

probability (emission ).

IVR Techniques

- In Phonetic recognition systems,

spoken words is break down into

small fundamental sound units

called phonemes. When

compared to word-based

recognition systems, phonetic

recognizers enable increased

accuracy in understanding larger

vocabularies.Language modeling

technology is also used to

heighten accuracy by comparing

recognized sounds to a list of

usage rules or constraints to

determine the probability of one

sound following another .28

IVR Phonetic Speech Recognition model

IVR Techniques

- Speech solutions are now enabling the development of IVR applications that go beyond rigid touch-tone interface models to exploit the flexibility offered by natural language processing.

- To aid recognition and reduce complexity, an "n-best list" of the most likely word

or phrase matches to the spoken utterance and associated confidence scores are then created and interpreted by the system.

- Natural language recognition and advanced user interfaces that conduct

interactive dialogues with users in order to complete transactions are driving the creation of the most versatile and robust applications ever developed for the IVR industry.

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IVR Techniques

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Speech Recognition System Engine

Speech Recognition is implemented in 5 types of systems :

I. Speaker dependent system - The voice recognition requires training before it can be used, which requires you to read a series of words and phrases.

II. Speaker independent system - The voice recognition software recognizes most users voices with no training.

III. Discrete speech recognition - The user must pause between each word so that the speech recognition can identify each separate word.

IV. Continuous speech recognition - The voice recognition can understand a normal rate of speaking.

V. Natural language - The speech recognition not only can understand the voice but also return answers to questions or other queries that are being asked.

Based on these SR-system types , the IVRS gained its categories .

IVR Techniques Speech Recognition IVRS types There are three main varieties of speech recognition IVRS :-

I. Touch-tone model\

in this IVR type the dialogues prompt the customer with one option. For example :System Prompt: "For checking information, press 1.“Caller Response: “1"

II. Directed dialogues model\

it is based upon predefined “grammars”, where dialogues prompt the customer with specific questions or options. For exampleSystem Prompt: "Would you like checking account information or rate information?"Caller Response: "Checking", or "checking account," or "rates."

I. natural language dialogues model\

it is based on statistically trained language models in which employ open questions with free-form responses. For example :System Prompt: "What transaction would you like to perform?"

II.Caller Response: "Transfer $500 from checking to savings.“

All the above IVRS types based on speech recognition but with different levels of sophisticated and expense as shown in the next slide 31

Audio Example

Audio Example

Program example

IVR TechniquesBut what are the Difference Between Natural Language and Directed Dialogue ? 

1.In directed dialogue model , the caller is directed through a series of yes/no or structured type questions with extremely limited acceptable responses.

2.So , the user has a negative experience and the company using the IVR has an unsatisfied customer who will likely need to be transferred to a live agent, which results in higher business costs.

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3. on the other hand, the natural language model does not only recognizes speech, but also interprets it. This means it has a much wider range of comprehension, allowing the user to speak more naturally.

Natural Language Processing (NLP) meaning

It is a field of ( computer science, artificial intelligence, and computational linguistics ) concerned with the interactions between computers and human (natural) languages and involves natural language understanding which enabling computers to derive meaning from human or natural language input , and sometimes involve natural language generation .

IVR Techniques IVR system advantages

1. The biggest advantage of IVR is saving time and money by :I. taking care most of frequent questions which are asked by customers .

II. Duration of the work , IVR can be available 24 hours a day to field questions and help customers with simple tasks.

III. IVR able to decrease the average duration of the call with a live operator even the half and that mean save a big amount of money .

2. An IVR system can make a small company look bigger.

3. It easier for businesses and organizations to use these automated phone services for supporting a “Buying and Selling” tasks by using the Advertisings and Promotions .

IVR system disadvantages

The greatest disadvantage of IVR systems is that many people simply dislike talking to machines. Older adults may have a hard time following telephone menus and lengthy instructions. And younger callers get frustrated with the slowness of multiple phone menus.

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The endThe endAt the end At the end

I want to thank dr.I want to thank dr. Fethullah for your help and Fethullah for your help and supportsupport

And sayAnd say

“ “ thank you to all attendees “ thank you to all attendees “

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