Make your IVR services more reliable with automated testing

An IVR (Interactive Voice Response) system allows a user to interact with an application via voice commands or their telephone keypad (DTMF). These systems are designed to guide callers through an automated voice menu, provide them with information (bank balance, order tracking, etc.), or redirect them to the right contact person.

An IVR system is based on a complex architecture combining hardware and software components. These include:

• DTMF inputs: each key on the telephone keypad produces an identifiable signal.
• Voice recognition: the IVR can analyze a user's spoken responses.
• The ARU (Audio Response Unit): provides an automatic voice response based on the data received.
• The ACD (Automatic Call Distributor): distributes calls to the right agents if necessary.
• Text-to-Speech (TTS): converts text into a voice message.
• Call flow: a tree structure that defines the user's path through the IVR.

A poorly configured or untested IVR can cause major frustration for users: incorrect redirection, incomprehensible messages, or input errors. Conversely, a well-tested IVR guarantees:

• Smooth navigation through menus
• A reduction in the volume of calls handled by human agents
• Improved data security
• A consistent experience regardless of the user or their language

Identity verification and security

IVR systems often ask security questions: PIN code, date of birth, email address, etc. These checks must be foolproof to prevent fraud, especially in sensitive sectors such as banking. The test must cover all cases: correct entry, errors, forgotten or compromised identifiers.

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Call routing and transfer

Proper routing is essential: a customer calling about an insurance issue should not be directed to the credit card service. Tests must verify the redirection logic based on user choices.

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DTMF input recognition

Each menu or submenu is based on DTMF input. It is crucial to test that each key triggers the correct prompt, without any interpretation errors. Poor recognition detracts from the experience and efficiency of the service.

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Repeating prompts

What happens if the user remains silent or does not understand the voice message? The system must repeat the instruction a defined number of times, then redirect or disconnect the call. This behaviour must be tested in all edge cases.

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Quality of voice messages

Prompts must be clear, audible and have good intonation. Speaking too quickly, using an inappropriate accent or failing to use punctuation can make the message incomprehensible. Audio testing is therefore an integral part of the process.

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Multilingualism and localisation

A good IVR system offers a choice of languages at the start of the call. Each language must have its own dedicated prompts, correctly localised, with the same voice quality standards. All paths must be tested for each language offered.

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Complete user journey (E2E tests)

A user journey is not just a series of menus: it is often a critical process. For example, a customer calls to block their bank card. They select ‘Card cancellation’ but end up on ‘Cheque book order’? This is a serious failure of the journey. Testing allows each key scenario to be validated.

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Automating DTMF testing allows you to simulate typical user journeys on a large scale.

Specialised tools (e.g. Hammer, Cyara, Empirix) can be used to cover load testing, voice quality, multilingual flows and regressions.

Automation reduces manual workload, speeds up acceptance cycles, and makes production rollouts more reliable.

IVR testing is a strategic issue for companies that rely on automated customer service. By automating testing, you secure your journeys, improve perceived quality, and optimise your support costs.

A well-tested IVR system means well-guided customers, a preserved reputation, and a service that inspires confidence.