Interactive Voice Response (IVR) is a powerful technology which enables businesses to provide exceptional customer service through automated assistance, routing, and information. IVR systems can process Speech and touch-tone inputs from callers, making it easy to streamline processes, reduce costs, and improve customer satisfaction.

1. How to build a personalized IVR
with DTMF and Speech
JUNE 6, 2023 Team Enablex
TECHTALKS
Interactive Voice Response (IVR) is a powerful technology which enables
businesses to provide exceptional customer service through automated
assistance, routing, and information. IVR systems can process Speech and
touch-tone inputs from callers, making it easy to streamline processes,
reduce costs, and improve customer satisfaction.
This technology has become an essential tool across various industries
and applications, including customer service, healthcare, banking and
financial services, surveys and polling, marketing, and order processing.
Using Voice APIs, modern speech to text technology and stacks such as
WebRTC, developers can create remarkably efficient IVR systems.
In this blog, we will learn how to build a modern, interactive IVR system.
Personalised IVR Systems: A key enabler for
customer experience and delight

2. By offering personalized support through IVR systems, businesses can
ensure that their customers receive a high level of service that meets their
specific needs. This technology allows customers to interact with the
business in a way that is convenient for them, and it can be tailored to suit
the needs of different businesses and organizations. With IVR systems,
businesses can save time and money while providing exceptional
customer service, making it a valuable investment for any business looking
to improve their customer experience.
IVR technology enables individuals to communicate with computer
systems by using either speech or touch-tone key inputs. Pre-recorded
voice messages or text-to-speech technologies, coupled with DTMF (Dual-
tone multi-frequency) interfaces, enable callers to access information and
provide information without the need to speak with a live agent using IVR
systems.
With the advancement of automatic speech recognition technology,
callers are now able to verbally express their needs over the telephone, and
IVR systems respond accordingly in real time. In addition, if the IVR system

3. cannot provide the information that the caller requires, it can direct the
caller to the appropriate representative for assistance.
Key paths to build an interactive voice response
system:
DTMF:
DTMF is a way to send digits over a voice channel using two separate
tones. Firstly, the DTMF input needs to be captured using a device such as
a telephone or IVR system. Following this, the DTMF tones are converted
into the corresponding digit using a DTMF decoder. After that, the digits
are interpreted, and the action to be taken is determined based on the
received input. Finally, the appropriate action is taken, such as routing the
user to a specific department or providing them with information.
Speech Recognition:
Speech recognition is the process of converting spoken words into text.
The speech input is captured using a device such as a microphone or
voice-enabled remote control. Next, a speech recognition engine is used
to convert the spoken words into text. The text is then interpreted, and the
action to be taken is determined based on the received input. Finally, the
appropriate action is taken, such as routing the user to a specific
department or providing them with information. For DTMF input, the IVR

4. system might play a menu prompt that lists available options or actions,
while for speech recognition input, the system might summarize the user’s
request and confirm that the system is processing their request.
The IVR system might play a menu prompt for DTMF input that lists
available options or actions, while for speech recognition input, the system
might summarize the user’s request and confirm that the system is
processing their request.
Benefits of Combining DTMF and Speech
Recognition in an IVR System
The benefits of combining DTMF and speech recognition in an IVR system
include:
• Improved user experience: Combining DTMF and speech
recognition allows users to choose the interaction method that they
prefer, which can improve the overall user experience. Some users
may prefer to use DTMF, while others may prefer to speak their
commands.
• Increased accessibility: By offering both DTMF and speech
recognition options, IVR systems can be made more accessible to
people with disabilities, such as those who are deaf or hard of
hearing.
• More natural interactions: Speech recognition can provide a more
natural and intuitive interaction for users, particularly when dealing
with complex menu options or lengthy prompts.
• Enhanced functionality: Combining DTMF and speech recognition
can enable IVR systems to offer more advanced functionality, such
as voice-based authentication or natural language processing.

5. • Improved efficiency: Speech recognition can speed up the
interaction process, reducing the time users spend navigating
through menus and prompts, and freeing up resources for more
complex tasks.
Build an IVR system with EnableX

6. Building, deploying, scaling, and updating modern IVR systems should be
straightforward with the right tools. That’s where EnableX voice
APIs come in – they empower you to build customized workflows and
solutions in a matter of days and make it easy to adapt and iterate as
needed for ongoing improvement.
The process is as straightforward as following these steps:
• Login to EnableX portal. If you do not have an account, Signup here.
• Create a voice project.
• Get Access to the App Credentials.
• Create voice prompts for your IVR system, either by audio Recording
or by using text-to-speech technology provided by the EnableX API
platform.
• Make sure they are saved in a compatible format for your API
platform.
• Buy a phone number from EnableX Inventory.
• Add phone number to the voice project.
• Configure your IVR system to play the appropriate prompts based on
user input, either through touch-tone keypad inputs (DTMF) or
speech recognition.
• Configure webhook URL for receiving event call back on Call State /
Play State changes.
EnableX provides a suite of features that can be used to create Interactive
Voice Response (IVR) systems for personalized support using DTMF and
speech recognition. These features include handling incoming voice calls,
making outbound voice calls, and processing call events.

7. • Handle incoming calls by processing the events received at the
webhook URL, which carry a unique identifier called the voice-id for
further API calls and events affecting the same inbound call.
• Make outbound calls Using proper API endpoint and request
parameters.
• Add prompts and play them
• Add prompts and play them via IVR: Once the call is connected, you’ll
need to add the prompts you created to the call and play them via the
IVR system. This will typically involve making additional API requests
to the platform to add the prompts and specify how they should be
played (e.g., via DTMF or speech recognition).
Incoming Call
When an incoming call is received by the EnableX Voice Service, the
system sends a notification to a web address you have configured,
containing details such as the caller’s phone number and a unique
identifier called the voice-id. You can use this identifier to track and
manage the call throughout its lifecycle. You can use DTMF tones or
speech recognition to gather information from the caller and customize
the response based on their input.
Webhook Event Sent By Voice Server When It Receives An Inbound Call
On EnableX Number
{
"voice_id" : "f1aa71c0-8f2a-4fe8-b5ef-9a330454ef58", //voice id of the incoming call,
"state": "incomingcall",
"from" : "from number",
"to" : "EnableX number",
"channel_id" : "" // Channel Id of the inbound call
"timestamp" : "2020-08-20T09:03:09.893Z"

8. }
Accept Call Voice API Can Be Invoked To Answer An Incoming Call On
Incoming Call Event Sent By Voice Server On Receiving An Inbound Call
On An EnableX Number.
const axios = require('axios');
const btoa = require('btoa');
require('dotenv').config();
var URL = "https://api.enablex.io/voice/v1/call/{voice_id}/accept";
URL = URL.replace("{voice_id}", "f1aa71c0-8f2a-4fe8-b5ef-9a330454ef58")
const HttpVerb = "PUT"
const APP_ID = process.env.ENABLEX_APP_ID;
const APP_KEY = process.env.ENABLEX_APP_KEY;
const authKey = btoa(`${APP_ID}:${APP_KEY}`);
const options = {
headers: {
"Authorization": "Basic ${authKey}",
"Content-Type": "application/json"
}
};
Successful And Error Response For Accept Call API
{
"voice_id": " f1aa71c0-8f2a-4fe8-b5ef-9a330454ef58",
"status": "success",
"timestamp": "2020-08-20T09:03:09.893Z "
}

9. Add Prompts
Use the EnableX API to add prompts to the IVR system. You can create
audio files or text-to-speech messages to prompt customers.
const data = {
"name" : "Service Name",
"from" : " from number ",
"to" : " EnableX number ",
"action_on_connect" : {
//Text to Speech with advance options
"play" : {
"text_to_speech_option" : {
"text" : "good morning welcome to text to speech demo",
//text will be played after 2 seconds.
"silence" : {
"type" : "leading",
"value" : "2000ms"
},
//text to be played after 2 seconds break",
"break" : {
"time" : "2000ms"
},
//text will be played in gentle voice
"express-as" : {
"style" : "gentle",
"text" : "text will be played in gentle voice"
},
//"text" : "text played at 30% higher rate and 50% volume"
"prosody" : {
"rate" : "+30.00%",
"pitch" : "high",
"volume" : "+50.00%",
},

10. //<say-as interpret-as="date" format="mdy">10-19-2016</say-as>
"say-as" : {
"interpret-as" : "date",
"format" :"mdy"
}
}
}
},
Receive DTMF And Speech Recognition
Use the EnableX API to recognize the customer’s input, either through
DTMF (Dual-tone multi-frequency) tones or through speech recognition.
{ {
"voice_Id": "f1aa71c0-8f2a-4fe8-b5ef-9a330454ef58", // Call_Id
"state": "dtmfcollected",
"digit": 12345,
"timestamp": "2017-02-16T10:52:00Z"
}
{
"voice_id": "6b211e69-c2cc-4a65-99e9-f7a3c6922796",
"state": "recognized | timeout | unrecognized",
"from": "CLI number", "to": "Destination number",
"text": "No, I'm not available.",
"reason": "Reczognized"
"playstate": "speech_recognized",
"timestamp": "2017-02-16T10:52:00Z"
"prompt_ref": "welcome-prompt"
}
Play Prompt

11. After receiving DTMF or Speech recognition inputs, you can play Prompts
depends on the specific use case and application. In general, after
receiving the input, the system should play a confirmation prompt to let
the user know that their input was received correctly.
const data = {
"prompt_name":"prompt file name to be played", //Identifier of the prompt as configured on the portal.
"text": "text to be played", // Text to be played by the TTS. NOTE: Either text or prompt will be be played
"language": "es-US", // Language to be spoken
"voice": "female", //For TTS only. Possible value is male or female
"dtmf": true, // If dtmf is true, it will wait for digits
"prompt_ref": "welcome_ref", // optional parameter for User specified prompt_ref.
"asr": true, // IVR via speech recognition enabled
"start_timeout" :10, // Initial Silence Timeout before user start speaking.
"recognizer_timeout": 1 // Wait before the voice server returns the result after silence.
}
To know more about outbound call, please see our blog Build and
Implement Personalised Voice Notification service.
An IVR system with DTMF and speech recognition can provide several
benefits to businesses, including faster call resolution, reduced call
volumes, personalized support, and improved customer experience.
EnableX’s interactive voice response system offers personalized support
by combining DTMF and speech recognition, allowing customers to
navigate through the system using touch tones or by speaking naturally.
Applications of interactive voice response
Interactive Voice Response (IVR) systems are commonly used in a variety
of industries and applications. Here are some examples:

12. • Healthcare: IVR systems are used in healthcare to provide patients
with appointment reminders, medication reminders, and other
health-related information. Patients can interact with the system to
confirm or reschedule appointments, or to refill prescriptions.
• Customer Service: IVR systems are widely used in customer service
to provide callers with automated assistance and routing. Callers can
be directed to the appropriate department or agent based on their
input or request.
• Banking and Financial Services: IVR systems are used in banking
and financial services to provide customers with account
information, transaction processing, and other banking services.
Customers can interact with the system to check account balances,
transfer funds, or pay bills.
• Surveys and Polling: IVR systems are used for surveys and polling to
collect feedback from customers or to gauge public opinion. Callers
can interact with the system to answer questions or provide
feedback on products, services, or policies.
• Marketing: IVR systems are used in marketing to allow customers to
request information, enter contests, or make purchases. Callers can
interact with the system to request brochures, coupons, or product
information, or to enter orders for products.
• Order Processing: IVR systems are used for order processing to
allow customers to place orders for products or services. Callers can
interact with the system to enter order information and payment
details to complete a purchase.
Personalized Support in healthcare industry with
DTMF and Speech Recognition

13. DTMF and speech recognition can be used to provide personalized support
in IVR systems:
DTMF For Account Identification: When a patient calls an IVR system for
healthcare support, they may be prompted to enter their registration
number or other identifying information using their phone’s keypad (DTMF).
This allows the system to quickly and accurately identify the patient and
access their medical history.
Speech Recognition For Natural Language Commands: Once the patient
is identified through DTMF, he may have prompted with a message such
as, “How can we assist you today?” The patient can then speak their
request or query using speech recognition. For example, the patient might
say “I need to refill my prescription,” or “Can you tell me the results of my
recent lab test?” The system can use natural language processing to
interpret the spoken words and respond accordingly, providing
personalized and conversational support.
Customized Menu Options: IVR systems can also use DTMF and speech
recognition to provide customized menu options based on the patient ‘s
medical history. For example, if the patient has diabetes, they might be
offered menu options to schedule an appointment with a diabetes
specialist or refill their insulin prescription.
Personalized Responses: By combining DTMF and speech recognition, IVR
systems can provide personalized responses to patients with personalized
medical advice based on their symptoms.
Best practices for building a healthcare IVR
system
Follow these IVR best practices to give patients the best possible
experience when they call you:

14. • Fully integrated IVR system: Healthcare organizations should
ensure that their IVR system is fully integrated with their electronic
health records (EHR) and other healthcare technologies. This can
help ensure that patient information is up-to-date and accurate, and
that healthcare providers have access to the information they need
to provide high-quality care.
• Use a friendly and reassuring voice: Patients may already be feeling
anxious or worried about their health, so using a friendly and
reassuring voice can help create a positive experience from the
start. Consider professional voice-over recording or high-quality
text-to-speech technology.
• Keep the IVR menu simple and clear: Patients may be calling in with
a specific health concern or question, so keeping the menu short and
easy to navigate can help them quickly get the information or
support they need. Aim to keep the main menu under 30 seconds and
provide clear options to direct patients to the appropriate
department or resource.
• Offer a direct option to connect with a live healthcare
professional: Some patients may require direct support from a live
healthcare professional, so providing this option upfront in the main
menu can help them get the support they need quickly and avoid
frustration.
• Provide language options: Patients from different backgrounds and
cultures may speak different languages, so offering IVR options in
multiple languages can help meet their needs and provide a more
inclusive experience. Consider adding language options based on the
demographics of your patient population.
• Provide an estimated wait time: Waiting on hold can be frustrating,
but providing an estimated wait time can help patients manage their

15. expectations and be more patient. Consider providing updates on
wait times at regular intervals or offering a call back option if the wait
time is long.
• Use the waiting time to educate patients: While patients are
waiting, you can use the opportunity to provide health education or
promote additional communication channels, such as email or online
chat. This can help patients feel more informed and engaged while
they wait.
• Choose appropriate hold music: Hold music can set the tone for the
patient’s experience, so choosing high-quality and calming music
can help create a positive experience. Consider using music that is
relevant to healthcare or soothing instrumental music.
• Integrate IVR with other channels: An integrated IVR system can
help provide a seamless patient experience across multiple
channels, such as online chat or email. This can help ensure that
patient information and context is carried across channels and
reduce the need for patients to repeat themselves.
• Regularly review and update the IVR menu: As healthcare
information and practices evolve, it’s important to regularly review
and update the IVR menu to ensure that patients are receiving
accurate and up-to-date information. Removing outdated messaging
or updating menu options can help keep the IVR system relevant and
useful for patients.
To improve their customer experience and increase efficiency, businesses
should consider implementing DTMF and speech recognition in their IVR
systems. This can help address common challenges such as long wait
times and inaccurate call routing, and provide personalized support
tailored to the customer’s needs and preferences. By doing so, businesses

16. can improve customer satisfaction and build stronger relationships with
their customers.
For more detailed information, read our documentation.
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Team Enablex
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