The Internet of Voice has arrived, and it’s changing the way we interact with our devices.
Siri points out your next turn in an unfamiliar town. Google Assistant scours the internet for directions on grilling salmon, and reads them to you while you work. The voicebot at the other end of the customer service line gets you results, without waiting or push-button menus. Call it the age of conversational computing—and the computer’s end of these conversations comes courtesy of a digital technology called text to speech, or TTS for short.
But TTS isn’t just for fancy new voice computing applications. For years it’s been used as an accessibility tool; as educational technology (edtech); and as an audio alternative to reading. In 2021, nearly a quarter of U.S. adults listened to audiobooks, and TTS may have helped make those experiences possible. All these examples just scratch the surface of what TTS can do.
In this article, we’ll describe the standard text to speech meaning and list some of the populations who benefit from TTS. Then we’ll discuss a few ways businesses can leverage voice technology to achieve mission-critical goals. Finally, we’ll walk you through the history of this continually developing field. Here’s your definitive introduction to TTS technology, starting with a fundamental question:
What is TTS? In other words, what does TTS mean?
Curious what today’s leading TTS actually sounds like? Explore ReadSpeaker’s TTS voices, complete with audio examples.
Text to Speech: Meaning and Science Behind the Term
Text-to-speech technology is software that takes text as an input and produces audible speech as an output. In other words, it goes from text to speech, making TTS one of the more aptly named technologies of the digital revolution. A TTS system includes the software that predicts the best possible pronunciation of any given text. It also bundles in the program that produces voice sound waves; that’s called a vocoder.
Text to speech is a multidisciplinary field, requiring detailed knowledge in a variety of sciences. If you wanted to build a TTS system from scratch, you’d have to study the following subjects:
- Linguistics, the scientific study of language. In order to synthesize coherent speech, TTS systems need a way to recognize how written language is pronounced by a human speaker. That requires knowledge of linguistics, down to the level of the phoneme—the units of sound that, combined, make up speech, such as the /c/ sound in cat. To achieve truly lifelike TTS, the system also needs to predict appropriate prosody—that includes elements of speech beyond the phoneme, such as stresses, pauses, and intonation.
- Audio signal processing, the creation and manipulation of digital representations of sound. Audio (speech) signals are electronic representations of sound waves. The speech signal is represented digitally as a sequence of numbers. In the context of TTS, speech scientists use different feature representations that describe discrete aspects of the speech signal, making it possible to train AI models to generate new speech.
- Artificial intelligence, especially deep learning, a type of machine learning that uses a computing architecture called a deep neural network (DNN). A neural network is a computational model inspired by the human brain. It’s made up of complex webs of processors, each of which performs a processing task before sending its output to another processor. A trained DNN learns the best processing pathway to achieve accurate results. This model packs a lot of computing power, making it ideal for handling the huge number of variables required for high-quality speech synthesis.
The speech scientists at ReadSpeaker conduct research and practice in all these fields, continually pushing TTS technology forward. These researchers produce lifelike TTS voices for brands and creators, allowing companies to set themselves apart across the Internet of Voice, whether that’s on a smartphone, through smart speakers, or on a voice-enabled mobile app. In fact, TTS voices are emerging in an ever-expanding range of devices, and for a growing number of uses (and users).
Who Uses TTS?
People with visual and reading impairments were the early adopters of TTS. It makes sense: TTS eases the internet experience for the 1 out of 5 people who have dyslexia. It also helps low literacy readers and people with learning disabilities by removing the stress of reading and presenting information in an optimal format. We’re progressing toward a more accessible internet of the future, and TTS is an essential part of that movement.
Already, many forward-minded content owners and publishers offer TTS solutions to make the web a place for all. Businesses and buildings are required to provide entryways for wheelchair users and those with limited mobility. Shouldn’t the internet be accessible for everyone, too? Yet, as technology evolves, so have the uses and the users of TTS. You may not need TTS, but you’ll certainly want it. Text to speech can make life easier and make you more efficient, however you define yourself.
Here are just a few of the populations benefitting from TTS technology already:
Recent studies suggest that learners profit most from mixed presentations. Some learners retain more information presented in both audio and visual formats, otherwise known as bimodal learning. A popular education framework called Universal Design for Learning (UDL) recommends bimodal learning to help every student be successful. Teachers of all grade levels who promote UDL use a combination of auditory, visual, and kinesthetic techniques with the help of technology and adaptable lesson plans.
Even if you identify as a kinesthetic or visual learner, science says adding an auditory method may help you retain information. And if nothing else, TTS makes proofreading a lot more manageable.
2. Readers on the Go
When you want to catch up on the news, podcasts and audiobooks only take you so far. So, if there’s an in-depth profile in The New Yorker or a longform article from The Guardian that you want to read, TTS can recite it for you. That frees you up to drive, exercise, or clean at the same time. Or you may just prefer listening over reading. According to leading experts in technology, online content will soon be automatically converted to audio so that more people can enjoy content on the go.
Dharmesh ShahKeynote at INBOUND 2016
The shortcuts TTS can provide are endless—from reading recipes while you cook to dictating instruction manuals when assembling furniture. The only limit to how much it can help is your own imagination.
4. Mature Readers
Understandably, older adults may want to avoid straining their eyes to read the tiny text on a smartphone. Text to speech can alleviate this issue, making online content easy to consume regardless of your skill with technology or the state of your vision.
5. Younger Generations
Offer technology to young people, and they’re likely to use it—whether it’s strictly “necessary” for them or not. In 2022, 70% of 18 to -25-year-old consumers turned on subtitles while viewing video content “most of the time,” not because they had hearing impairments, but because it was convenient. And so many Tik Tok users took advantage of the app’s TTS feature that rival Instagram rolled out their TTS in 2021. Meanwhile, a survey of college undergraduates found that only 5% of respondents had a disability necessitating the use of assistive technology—but at least 18% of the students considered each technology “necessary.” The point is, Generation Z uses TTS not just as an accessibility tool, but as a preference.
6. Readers With Visual Impairments or Light Sensitivity
Older adults aren’t the only ones who want to avoid straining their eyes on screens. Many people have mild visual impairments or suffer from sensitivity to light. Think of people with chronic migraines, for instance. Thanks to TTS, these users can be more productive on days when staring at screens seems like a pain too much to bear.
In fact, medical studies advise that exposure to light at night, particularly blue light from screens, has adverse health effects. It not only disrupts our biological clocks, but it may increase the risk of cancer, diabetes, heart disease, and obesity rates. Text to speech offers users a safer way to consume written content, without staring at a screen.
7. Foreign Language Students
Studies show that listening to a different language aids students in learning the new dialect. Text to speech can help with that. ReadSpeaker is an international TTS software company, featuring over 50 languages and more than 150 voices, all based on native speakers.
With ReadSpeaker, foreign language students can get a feel for pronunciation, cadence, and accents. One feature that’s especially helpful in this regard is the ability to have words highlighted as they’re read aloud, which can help students feel confident in their pronunciation of new vocabulary.
8. Multilingual Readers
New generations raised in multilingual households may understand their (grand)parent’s language, but they may not feel fluent enough to read, write, or speak it. This is common in many communities, where the home language is not studied in school. For second and third generations who want to maintain or strengthen their bonds to their mother lands, ReadSpeaker can make articles, newspapers, and other literature accessible and understandable through speech.
9. People With Severe Speech Impairments
A speech-generating device (SGD), also known as a voice output communication aid (VOCA), is useful for those who have severe speech impairments and who would otherwise not be able to communicate verbally. Grouped under the term “augmentative and alternative communication (AAC),” SGDs and VOCAs can now be integrated into mobile devices such as smartphones.
Stephen Hawking, who suffered from ALS, and also renowned film critic Roger Ebert were among the most well-known users of SGDs using TTS technology. So, who uses TTS? Many people, for many different reasons. And if you’re looking for a way to solve today’s business challenges, TTS may be the technology you need.
To learn more about ReadSpeaker’s TTS services, check out their products or FAQ.
TTS Technology for Business
When ReadSpeaker AI first began synthesizing speech in 1999, TTS was primarily used as an accessibility tool. Text to speech makes written content across platforms available to people with visual impairments, low literacy, cognitive disabilities, and other barriers to access. And while accessibility remains a core value of ReadSpeaker’s solutions, the rise of voice computing has led to an ever-growing range of applications for TTS across devices, especially in business.
Here are just a few of the powerful corporate use cases for TTS in today’s voice-first world:
- Conversational interactive voice response (IVR) systems, as in customer service call centers
- Voice commerce applications, such as shopping on an Amazon Alexa device
- Voice guidance and navigation tools, like GPS mapping apps
- Smart home devices and other voice-enabled Internet of Things (IoT) tools
- Independent virtual assistants like Apple’s Siri, but for your own brand
- Experiential marketing and advertising solutions, like interactive voice ads on music streaming services or branded smart speaker apps
- Video game development, with dynamic runtime TTS for accessibility features, scene prototyping, and AI non-player characters
- Company training and marketing videos that allow creators to change voice-overs without tracking down original voice talent for ongoing recording sessions
Chances are, you’ve already experienced TTS through some or all of these examples. If you run a business, you might have even helped produce a voice-first device or experience. Given this broad usage, it’s safe to say TTS is here to stay. But it isn’t exactly a new technology.
Types of TTS Technology, Then and Now
Mechanical attempts at synthetic speech date back to the 18th century. Electrical synthetic speech has been around since Homer Dudley’s Voder of the 1930s. But the first system to go straight from text to speech in the English language arrived in 1968, and was designed by Noriko Umeda and a team from Japan’s Electrotechnical Laboratory.
Since then, researchers have come up with a cascade of new TTS technologies, each of which operates in its own distinct way. You may ask, “How does text to speech work?” The answer depends on which TTS technology you’re using. Here’s a brief overview of the dominant forms of TTS, past and present, from the earliest experiments to the latest AI capabilities.
Formant Synthesis and Articulatory Synthesis
Early TTS systems used rule-based technologies such as formant synthesis and articulatory synthesis, which achieved a similar result through slightly different strategies. Pioneering researchers recorded a speaker and extracted acoustic features from that recorded speech—formants, defining qualities of speech sounds, in formant synthesis, and manner of articulation (nasal, plosive, vowel, etc.) in articulatory synthesis. Then they’d program rules that recreated those parameters with a digital audio signal. This TTS was quite robotic; these approaches necessarily abstract away a lot of the variation you’ll find in human speech—things like pitch variation and stresses—because they only allow programmers to write rules for a few parameters at a time. But formant synthesis isn’t just a historical novelty: it’s still used in the open-source TTS synthesizer eSpeak NG, which synthesizes speech for NVDA, one of the leading free screen readers for Windows.
The next big development in TTS technology is called diphone synthesis, which researchers initiated in the 1970s and was still in popular usage around the turn of the millennium. Diphone synthesis creates machine speech by blending diphones, single-unit combinations of phonemes and the transitions from one phoneme to the next: not just the /c/ in the word cat, but the /c/ plus half of the following /ae/ sound. Researchers record between 3,000 and 5,000 individual diphones, which the system sews together into a coherent utterance.
Diphone synthesis TTS technology also includes software models that predict the duration and pitch of each diphone for the given input. With these two systems layered on one another, the system pastes diphone signals together, then processes the signal to correct pitch and duration. The end result is more natural-sounding synthetic speech than formant synthesis creates—but it’s still far from perfect, and listeners can easily differentiate a human speaker from this synthetic speech.
Unit Selection Synthesis
By the 1990s, a new form of TTS technology was taking over: unit selection synthesis, which is still ideal for low-footprint TTS engines today. Where diphone synthesis added appropriate duration and pitch through a second processing system, unit selection synthesis omits that step: It starts with a large database of recorded speech—around 20 hours or more—and selects the sound fragments that already have the duration and pitch the text input requires for natural-sounding speech.
Unit selection synthesis provides human-like speech without a lot of signal modification, but it’s still identifiably artificial. Meanwhile, throughout all these decades of development, computer processing power and available data storage were making rapid gains. The stage was set for the next era in TTS technology, which, like so much of our current era of computing, relies on artificial intelligence to perform incredible feats of prediction.
Remember the deep neural networks we mentioned earlier? That’s the technology that drives today’s advances in TTS technology, and it’s key to the lifelike results that are now possible. Like its predecessors, neural TTS starts with voice recordings. That’s one input. The other is text, the written script your source voice talent used to create those recordings. Feed these inputs into a deep neural network and it will learn the best possible mapping between one bit of text and the associated acoustic features.
Once the model is trained, it will be able to predict realistic sound for new texts: With a trained neural TTS model—along with a vocoder trained on the same data—the system can produce speech that’s remarkably similar to the source voice talent’s when exposed to virtually any new text. That similarity between source and output is why neural TTS is sometimes called “voice cloning.”
There are all sorts of signal processing tricks you can use to alter the resulting synthetic voice so that it’s not exactly like the source speaker; the key fact to remember is that the best AI-generated TTS voices still start with a human speaker—and TTS technology is only getting more human. Current research is leading to TTS voices that speak with emotional expression, single voices in multiple languages, and ever more lifelike audio quality. Explore the languages and voices available with ReadSpeaker TTS.
That’s probably more technical information than you need, but it covers the basic text-to-speech meaning and then some. And if you still have questions, follow the links below.
For more information about text to speech, help creating your own branded voice, or access to market-ready TTS voices in more than 30 languages, contact ReadSpeaker today.
Text-to-Speech Basics: What Is TTS and Who Uses It? ›
Text-to-speech (TTS) is a very popular assistive technology in which a computer or tablet reads the words on the screen out loud to the user. This technology is popular among students who have difficulties with reading, especially those who struggle with decoding.Who uses TTS? ›
Who Uses TTS? People with visual and reading impairments were the early adopters of TTS. It makes sense: TTS eases the internet experience for the 1 out of 5 people who have dyslexia.What is TTS used for? ›
Text-to-speech (TTS) is a type of assistive technology that reads digital text aloud. It's sometimes called “read aloud” technology. TTS can take words on a computer or other digital device and convert them into audio.What is TTS for text? ›
What is text to speech. Text to speech is also known as TTS, read aloud, or even speech synthesis. It simply means using artificial intelligence to read words aloud be; it from a PDF, email, docs, or any website.Does TTS work for everyone? ›
Moreover, text-to-speech messages come in handy for removing any language barriers or for people who experience difficulties reading. However, Discord's TTS only works for Windows and Mac users.What is a TTS mean? ›
text-to-speech (a computer program that changes text into spoken language)What is the disadvantage of TTS? ›
While text to speech voices can be helpful in some situations, there are also some drawbacks to using them. One of the main problems is that they can often sound robotic and unnatural. This can make it difficult for listeners to understand what is being said, and it can also be quite jarring to hear.What are the cons of TTS? ›
When it comes to text-to-speech (TTS) audio, there are a few drawbacks to consider. One is that the quality of TTS audio is generally lower than that of recorded human speech. This is because TTS systems rely on synthesized speech, which can sound robotic and unnatural.Who invented text to speech? ›
The first full text-to-speech system for English was developed in the Electrotehnical Laboratory, Japan 1968 by Noriko Umeda and his companions (Klatt 1987).Why do people use TTS on TikTok? ›
Apart from making content more inclusive, text to speech voices TikTok offers have a few other perks, making them very popular among creators. Accessibility. TikTok TTS voice online feature allows creators to cater to a wider audience, making their content more convenient and entertaining to consume for everyone.
What is TTS for learning? ›
TTS is a great learning tool, and it's considered UDL (Universal Design for Learning). Teachers can use it to help students advance in their English learning studies. Most TTS software today operates on the cloud, meaning it is easily accessible on multiple devices.Does TTS cost money? ›
Google Cloud Text-to-Speech Pricing
Pricing: Text-to-Speech is priced based on the number of characters sent to the service to be synthesized into audio each month and starting from $4.00 USD per 1 million characters after free usage limit is reached.
You can also manually set the caret position and tap 'Play,' TTSReader will play from the newly selected position. All of this is totally free.What is the most realistic TTS voice? ›
A few of the top tools and services with the most realistic text to speech output are IBM, Azure, Google, Amazon, etc. TTS services.What do streamers use for TTS? ›
Users can add TTS to their Twitch channels in two primary ways: via Streamlabs or StreamElements, which are two well-known streaming platforms that most streamers use.What is TTS in social media? ›
Text-to-speech (or TTS) is type of a speech synthesis app that can easily improve accessibility for Facebook users. It allows you to convert any type of text into an audio file.What is the difference between TTS and TT? ›
Engine, Transmission, and Performance
A turbocharged 2.0-liter four-cylinder engine lives under the hood of the TT, and it generates 228 horsepower and 258 lb-ft of torque. The TTS gets a beefed-up version of this engine that's tuned to deliver 288 horsepower and 280 lb-ft of torque.
What Does “TTS” Mean? This term is frequently used online and in text messages to stand for “text to speech.” This is the title given to a program that allows a computer to convert a person speaking into words on a screen generated by the computer.How accurate is TTS? ›
As a result, they generate many types of incorrect readings for numerals, showing an accuracy of only 55%–87.7% 4  . Specifically, they seldom produced the correct pronunciation when Arabic numerals were combined with homographs. ...Is TTS considered AI? ›
The text-to-speech (TTS) assistive technology uses artificial intelligence to translate information written in a human-readable form in one language into audio, voice, or speech with a human accent. Such systems turn text into audio or speech output using AI-driven algorithms as the input.
What is TTS communication? ›
What is Text-To-Speech? (TTS) Text-to-Speech (TTS) is technology that reads digital text aloud, usually with computer generated voices. Typically there are options to customize voices and reading speed.What are the benefits of TTS status? ›
Trader tax status also allows day traders to make an election for something called mark to market. A day trader who does not have trader tax status can only write off up to $3,000 in trading losses when they file taxes, but those with mark to market election can claim greater losses, if applicable.Can you get rid of TTS? ›
Search “Text to Speech” Tap on the right application. Toggle “TTS OFF” from the main screen.Is TTS machine learning? ›
Text-To-Speech Synthesis is a machine learning task that involves converting written text into spoken words. The goal is to generate synthetic speech that sounds natural and resembles human speech as closely as possible.Who is the voice behind TTS? ›
Behind TikTok's text-to-speech voice "Jessie" is radio host and voice over artist Kat Callaghan.What is the TikTok text to speech controversy? ›
However, the introduction of Tiktok voice generator Text-to-Speech has not been without controversy. TikTok was forced to switch to a new voice after the original actor filed a lawsuit, claiming that she was never given permission to be featured in the app.Which TTS is used in memes? ›
- 1) VoxBox.
- 2) Speechify.
- 3) TTS Tool.
- 4) MagicMic.
With Instagram's text to speech (TTS) feature, you can add a voiceover to your Reel without uttering a single syllable! Just type your script, choose your preferred voice, and voila! You've got a killer voiceover to go with your Reel.How do you voice chat with TTS? ›
Open Discord and send a voice message in any channel you want. Type “/tts” followed by a space, and then type your message. Send the message. The slash command will not appear anymore in your message, but all the users will hear your message aloud in the channel you have sent a message by a voice bot.How do streamers keep talking? ›
Narrate What You Are Doing on Stream
If you have nobody to talk to, narrate what you are doing. Give play-by-plays of your actions, point out special tricks you are using, or laugh at something that happens unexpectedly. Don't let yourself zone-out. Produce something that you would want to watch.
Why did TikTok get sued for a sound? ›
According to records, TikTok had used voice snippets from a voiceover gig that Standing had done for the Chinese Institute of Acoustics. The job required Standing to record around 10,000 sentences to be used mainly for translation purposes.Who sued TikTok because of a sound? ›
TikTok has agreed to settle a lawsuit with Bev Standing, the voice actress who said she was behind the app's original text-to-speech voice. Standing sued TikTok in May, saying that the app was using her voice without permission.