Text-to-speech (TTS) technology has been around for decades, but has evolved dramatically in recent years. Services can now not only offer more realistic speech, but even fully-generate AI videos once a user enters text into a textbox.
Thanks to AI voice APIs, more and more apps and platforms are able to access these incredible capabilities without having to create their own text-to-speech technology. Developers can incorporate these services to quickly and seamlessly get the benefits of TTS to their end-users.
What is an AI Voice API?
Users who want to synthesize human-like speech likely need an AI Voice. These generate spoken word from a combination of media sources including audio or video samples, like a person speaking, and a body of text, like a manuscript. Many AI voice software packages offer front-end user interfaces for simple and direct sample outputs.
Using an API for AI voice means developers can add these capabilities to their apps in minutes–without any coding required.
A few of the applications that rely on AI Voice technology include:
- AI video generation
- Chatbots and Large language models (LLMS)
- Hardware reading accessibility in e-readers
- Media editing for podcast or video production
Text-to-speech API vs AI Voice API vs AI Voice Generator API
Text-to-speech or TTS refers to the specific process of entering text and pre-recorded sounds to form synthesized speech. It most commonly uses pre-recorded vocal sounds from a narrator to form spoken words. Enter characters into a text-to-speech API and it will read it back aloud. Although they’re always changing and improving, good examples include voices that have been around for a long time, like Apple’s Siri or Amazon’s Alexa.
In traditional text-to-speech, a voice actor records a library of neutral vocal sounds that are stored in a database and associated with a dictionary spanning every necessary combination of inflections to form clear words.
Here, software outputs semi-realistic, but monotone speech. The sound of the spoken word is limited to those in the voice recordings. They are often bundled with operating systems for accessibility.
Text-to-speech Features
- Easily identifiable as computer-generated
- Found in software like operating systems
- Use-cases like accessibility
With the development of machine-learning, AI algorithms allow for more realistic speech. Using a database or small sample, AI can apply inflections and smoother transitions between words and sounds for more natural-sounding pronunciations.
As a result, most text-to-speech services are evolving to utilize AI voice APIs. AI has also evolved the text-to-speech process so that responses can be generated automatically in real time. Services like AI chatbots or even Siri and Alexa use real-time responses where text is generated through algorithms rather than being typed out manually in advance. As a result, almost any synthesized voice today can be referred to as an AI voice.
AI voice generators allow for highly-customizable output. AI algorithms can now perform multiple tasks in the voice-production process to create unique spoken words faster than ever, and with less recording time. Rather than a full database of vocal sounds, techniques like voice cloning make it possible to compile a synthesized voice from a small sample.
AI voice generators can take an individual sample, uploaded by a user, and synthesize a personalized AI voice. Using machine-learning, these generators are able to map speech patterns to create a lifelike voice.
AI Voice Generator Features
- High-quality, often indistinguishable from human speech
- Customizable inflections, pitch, timbre
- Convert speech into different languages
- Use-cases like voiceovers, podcasts
Best AI Voice API Online
There are plenty of reliable options for developers looking to quickly integrate AI Voice into their services. Some services offer more nuanced control and others offer more advanced features. Read on to see which APIs provide the maximum value.
1. Tavus
Tavus API equips developers with an advanced AI voice generator to integrate text-to-speech and video generation into their platforms. Utilizing neural networks and generative AI, it allows users to convert text into lifelike speech in minutes. It offers complete voice cloning, which creates a virtual and realistic voice, all using a short clip to produce mimicked speech.
Beyond just audio-output text-to-speech, Tavus’ AI voice generator API revolutionizes the process to offer fully-rendered videos. Unlike other software, it constructs each component from the ground up to create the most realistic render possible. It combines AI voice cloning with its avatar AI to create a virtual talking head that speaks with text input.
The heart of this process is Tavus’ Phoenix model, which uses neural radiance fields to map and render a complete, and dynamic 3D avatar. Eye movements, facial expressions, and lip synchronization are all lifelike. Once rendered, all the user needs to do is provide the written prompt for the avatar to speak; not unlike a teleprompter for a newscaster. This avatar is then used to generate hyper-realistic videos of a speaker.
The Tavus API allows developers to build immersive AI-generated video experiences into their applications.
Tavus’ replica technology, speed, and scale offers countless use cases. It really shines in cases that require high-fidelity video and voice output like ecommerce and learning management systems.
Ecommerce developers can embed AI avatars on product pages to engage users in real-time discussions about features and benefits.
Learning management system developers can enable personalized coaching videos with tailored feedback on metrics, milestones, and performance improvements.
Key features:
- AI Voice and video cloning
- Generates exceptionally realistic talking head videos
- Natural face movements and expressions are accurately synchronized with input
- Control for inflection, tone, pitch
- Users can train personal replica with 2 minutes of video footage
- Hummingbird model powers the Lip Sync and Dubbing APIs
- Video Campaign API allows developers to provide an end-to-end video campaign experience out of the box
- Produces videos in over 30 languages
- Integrate using a single API call
Create personalized media experiences that captivate audiences at scale.
2. Amazon Polly
Amazon Polly is a text-to-speech API that allows you to transcribe text into different languages. Its primary use case is app development. It provides programmers the opportunity to incorporate features like speech-activation. It supports Java, Node.js, .NET, PHP, Python, Ruby, Go, C++, HTTP, Android and iOS.
Key features:
- Synthesize speech into multiple languages
- Change pitch, rate, and loudness
- Export output to an mp3 file
3. Descript
Descript is an AI service that is geared toward end-user media development, for work like podcasts and videos. Its text-to-speech tools focus primarily on narration. It includes speech editing like dubbed audio speech repair, voiceovers, and voice cloning.
Key features:
- Perform voice cloning
- Generate different inflections
- Access a library of voices
4. ElevenLabs
ElevenLabs is a text-to-speech service that hosts several options, including a database of thousands of pre-made voices spanning 28 languages. It focuses on providing real-time API services for developing chatbots, websites, and other SaaS.
Key features:
- Use premade, generated, and cloned voices
- Pair with chatbots, language models
- Choose from 29 languages
5. Google Cloud Speech
Google Cloud Speech is a text-to-speech API primarily designed to offer integration across app and hardware ecosystems. It uses Google’s DeepMind AI to generate near human speech. It allows you to use Speech Synthesis Markup Language or SSML to indicate pauses and inflections in the spoken output.
Use case: Voicebots in contact centersKey features:
- Use SSML to change pitch, rate, and loudness
- Export to various audio formats
- Choose from more than 40 languages
6. IBM Watson
IBM Watson is an AI suite that provides a cloud text-to-speech service. It’s designed for app development and commercial services, offering end-to-end encryption. It allows programmers to adjust specific speech qualities including strength, breathiness, and timbre.
Key features:
- Choose from different speaking styles
- Create custom voice from a one-hour recording
- Use SSML to adjust pronunciation, volume, pitch, speed
7. Listnr
Listnr is an AI text-to-speech platform that acts as a centralizing API for text-to-speech voice services. It allows programmers to integrate access to multiple voice databases into one, including those from Amazon Polly, Google WaveNet, IBM Watson and Microsoft Azure.
Key features:
- Programmable API with SSML
- Provides access to over 1000 voices and 142 languages
- Also offers voice cloning
8. Lovo
Lovo is an AI multimedia service that offers a text-to-speech and AI voice API. It features an online interface with tools designed to assist users in media creation in the form of video, photo, and text editing. Its text-to-speech service is designed for high-quality recordings.
Key features:
- Includes generative AI for voice cloning
- Over 100 languages and accents
- Speech-to-text with auto-subtitle generation
9. Microsoft Azure
Microsoft Azure is a software development service designed for creating applications. It includes an AI Voice API known as AI Speech. Its text-to-speech functions are designed to create conversational interfaces with natural-sounding voices. It supports C#, C++, Go, Java, JavaScript, Objective-C, Python, and Swift programming languages.
Key features:
- Clones voices from 30-minute recordings
- Applies SSML instructions for a custom synthesis
10. MurfAI
MurfAI is a text-to-speech service designed around content creation and software integration. It offers direct integrations with Canva, Google Slides, Adobe Audition, Adobe Captivate, and websites as HTML Embed Code. It also features a front-end application for Windows and incorporates with platforms that support Microsoft Speech API. It features a voice generator, voice cloning, voiceover language translation, and app development.
Key features:
- Designed for creating audiobooks, podcasts, sound files
- Provides an API for business for conversational AI
- Includes over 20 languages
11. Play.ht
Play.ht integrates several AI voice databases to form a wider range of voices across different languages. It combines voices from Amazon, Google, IBM, and Microsoft. Its AI voice API targets audio publishing, audiobooks, conversational AI, interactive voice response (IVR) systems like call-centers, and e-learning.
Its API includes International Phonetic Alphabet (IPA) symbology so users can customize pronunciations. It provides an audio widget to integrate with websites.
Key features:
- Includes real-time voice generation
- Over 142 languages and accents
- Apply custom pronunciations
12. Speechify
With Android and iOS apps and browser extensions, Speechify applies text-to-speech to document-reading across devices. Its web interface called Studio allows users to perform voice-overs in 40+ languages and dubbing in 20+ languages. It also features a voice-cloning service that provides 100,000 characters per month and access to commercial usage rights.
Key features:
- Offers a reading app for news and articles
- Hosts voices from famous actors and influencers
- Text-to-Speech API still in development
More About AI Voice APIs
Now that we’ve reviewed the best providers, let’s address some frequently asked questions about AI voice APIs.
Is there a free AI voice API?
While there are many free text-to-speech products, most AI voice APIs are paid. Some AI voice APIs do offer a free trial or a demo. Tavus API provides developers with a free tier, giving access to conversational video and video generation with 5 stock replicas and 3 minutes of credit for both features.
It’s a great way to explore the platform before committing. No personal replicas or overage fees in the free plan. You can sign up for free here.
Is it legal to use AI voice?
With the news around deepfakes, the legality of using an AI voice can be confusing. After all, there are many bad-faith actors that use AI for disinformation. Some AI voice services even specifically feature real individuals like celebrities.
In most instances, the attributed speaker is consenting, contracted, or most likely paid royalties for providing their voice. If you have doubts or concerns, it is best to check the service’s website for information on how they source voices.
Tavus is committed to safety and safe usage. The platform is built with privacy and security front-of-mind so developers can focus on user experience.
As part of their APIs, Tavus employs a suite of safety checks including voice identification and user consent to ensure only a user can clone their own voice and hold the keys to their likeness. The process is handled on behalf of end-users by Tavus.
Can I make an AI of my voice?
Yes - in fact, some AI voice APIs are designed to do just that. While you can’t clone another person’s voice without their consent, you can always make an AI of your voice, and Tavus is a great place to start.
Choose the Best AI Voice API
There are many AI voice API options to simplify a workflow, with each offering different features and advantages. Using an AI voice API can drastically boost project performance all while streamlining production. This removes the burden of building AI voice capabilities on your own, saving thousands of developer hours and allowing you to launch new capabilities in weeks or months.
The rapid development of AI has created a quickly-evolving toolkit for content development. With so many options, it can be hard to know where to start. On the cutting-edge of the industry, Tavus API equips developers with the tools to create the most realistic voice and video experiences out there. Tavus’ Replica API produces a virtual clone of a user with just two minutes of video and also offers a selection of stock replicas so users don’t have to create their own. It can generate video from a single API call and just one parameter.
Enabling users to create high-quality audio and video recordings to scale has never been easier.
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