Text-to-Speech
Text-to-speech is the technology that turns written text into spoken audio, using a synthetic voice, so that software can read content or answer people aloud.
Definition
Text-to-speech, often shortened to TTS, takes a sentence and generates the sound of someone saying it. Early systems stitched together recorded fragments and sounded robotic. Current neural voices model rhythm, stress and intonation, and can sound close to a human speaker, in many languages and with a choice of voice styles.
Quality is judged by listening: is the pronunciation correct, including names and numbers, is the pace comfortable, does the intonation fit the sentence, and how quickly does the audio start? In a live conversation, a delay before the voice begins is noticed more than a slightly imperfect voice. Settings such as speed, pauses and the choice of voice can be adjusted for the audience.
A voice matters for trust. A pleasant, clear voice makes a conversation easier, while a flat or mispronounced one makes people stop listening. Because synthetic voices can be very convincing, people should be told they are speaking with an AI, and a voice should never imitate a real person without their consent.
Key points
- It generates spoken audio from written text; it is also called speech synthesis.
- Neural voices model rhythm and intonation and sound far more natural than older systems.
- Check pronunciation of names, acronyms and numbers in every language you use.
- Start-up delay matters in live conversations.
- Tell people when the voice is synthetic and never clone a real voice without consent.
Example
A university builds a spoken check-in for first-year students in French and English. The team listens to the test audio and corrects how the names of two campuses and several programme acronyms are pronounced before launch.
Frequently asked questions
What is the difference between text-to-speech and speech-to-text?
They are opposites. Text-to-speech produces audio from text, while speech-to-text produces text from audio. A voice AI agent uses both.
Can a synthetic voice sound human?
Neural voices can sound very natural, but they can still stumble on rare names, abbreviations or emotion. Listening tests with your own content are the only reliable check.
Is it acceptable to hide that the voice is synthetic?
It is better practice, and in some places a legal expectation, to tell people they are talking to an AI. Check the rules that apply to you with a legal advisor.
Related terms
AI conversations, human decisions
Passisto holds structured voice conversations with candidates, employees, clients and students, and turns them into reports your team can act on.