Open Source Text to Speech: Benefits, Applications & Best Tools

Open source text to speech technology offers endless possibilities. Learn about the benefits and applications. Get started today.

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Open Source Text to Speech is revolutionizing access to Text to Speech technology. By leveraging open-source software, developers can create high-quality, customizable speech synthesis applications. This technology not only benefits those with disabilities but also improves user experiences across various industries. With Open Source Text to Speech, the possibilities are endless. Let's explore this cutting-edge technology together.  

Table of Contents

What Is TTS Technology?

AI bot using Open Source Text To Speech

Speech synthesis, also known as text-to-speech synthesis, is a technology that converts written text into spoken words. It’s commonly used in various apps on Windows, Android, and MacOS systems to assist visually impaired users, automate voice responses in telecommunication systems, or provide real-time narration in multimedia applications.

This technology utilizes advanced algorithms and artificial intelligence to replicate the nuances and subtleties of human speech, including intonation and pronunciation. These algorithms analyze the input text, decipher its linguistic and phonetic details, and generate a corresponding audio waveform. This waveform is then transformed into a human-like voice, often capable of producing speech in different languages like English or Chinese.

What Is An Open Source Text To Speech?

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Open source text-to-speech tools play a vital role in the domain of speech synthesis. These tools are essential in converting written text into spoken words, making them valuable in various applications such as accessibility features for differently-abled individuals, automated voice responses in customer service systems, and virtual assistants in smart devices.

Open Source Collaboration in Software Development

Open source software is designed to grant public access to the software's source code, encouraging collaboration among developers. This accessibility allows developers to study, adjust, and distribute the software to suit their specific requirements. As a result, open source TTS engines evolve rapidly through the collective efforts of a global community of developers, making them more reliable and adaptable.

Functionalities and Accessibility of Open Source TTS Software

Within the TTS domain, open source refers to tools and libraries that provide functionalities like text-to-speech, speech recognition, and transcription. These tools' source codes are often hosted on platforms like GitHub, making it easier for developers across the world to collaborate, improve, and customize these systems. Open source TTS software is mostly free to use, making it accessible to a broader audience.

How Does Open Source Speech Synthesis Work?

workings of Open Source Text To Speech

Open source speech synthesis tools employ similar methodologies as proprietary systems but with the added advantage of transparency and customization. Developers can access, modify, and optimize these tools according to their specific use case.

Tool Integration and Development

Typically, these tools come with a command line interface and APIs, allowing users to integrate them into their workflows. Python and Java are common languages used in their development. The system takes the input text, pre-processes it into a format understandable by the machine learning model (often a transformer-based model), and then generates the speech waveform. This waveform can be saved as an audio file, like a WAV file, or used in real-time applications.

Documentation and Setup Assistance

Most tools also include extensive docs and tutorials, aiding users in understanding the tool’s dependencies and helping them set up the environment, whether it be Linux, Windows, or MacOS. In some systems, the processing can be offloaded to a GPU for faster results, especially important in real-time speech synthesis.

Benefits Of Open Source Text To Speech (TTS) Technology In The TTS Domain

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Accessibility and Affordability

Open-source TTS solutions are incredibly beneficial due to their accessibility and affordability. Since open-source TTS platforms are free, they are available to a wide range of users, including those who may not have the financial resources to purchase commercial TTS software. This inclusivity ensures that everyone has access to the necessary tools to communicate effectively, regardless of their financial situation.

Customization and Flexibility

One of the key benefits of open-source TTS technology is its customization and flexibility. With open-source TTS software, users have the freedom to modify and customize the code to suit their specific needs. This allows developers to tailor the TTS engine to accommodate various languages, accents, and voices, providing a level of flexibility that is not typically available with proprietary software.

Collaboration and Community-Driven Development

Open-source projects thrive on collaboration and community-driven development. The contributions of developers, researchers, and enthusiasts from around the world lead to rapid innovation and continuous improvement of TTS technology. This collaborative approach ensures that open-source TTS solutions are constantly evolving, becoming more robust and feature-rich with each iteration.

Empowering Developers and Researchers

Open-source TTS technology empowers developers and researchers by providing them with the tools and resources they need to experiment, innovate, and explore new ideas. With access to the source code and a supportive community, developers can enhance their skills and contribute to the advancement of TTS technology. This empowerment drives progress in the field and leads to exciting developments in open-source TTS solutions.

10 Best Open Source Text To Speech (TTS) Models

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1. Unreal Speech

Unreal Speech offers a low cost, highly scalable text-to-speech API with natural-sounding AI voices which is the cheapest and most high-quality solution in the market. We cut your text-to-speech costs by up to 90%. Get human-like AI voices with our super fast/low latency API, with the option for per-word timestamps. With our simple easy-to-use API, you can give your LLM a voice with ease and offer this functionality at scale.

If you are looking for cheap, scalable, realistic TTS to incorporate into your products, try our text-to-speech API for free today. Convert text into natural-sounding speech at an affordable and scalable price.

2. MaryTTS

MaryTTS is a Java-based open source text to speech system, featuring high-quality voices and an extensive toolkit for generating new voices. It provides support for multiple languages and a customizable HTML interface.

3. Coqui TTS

A powerful TTS tool developed by Coqui, it leverages advanced transformer models for high-quality speech synthesis. Coqui TTS’s user-friendly Python interface, extensive documentation, and community support make it a preferred choice for developers.

4. Mycroft’s Mimic

Mycroft offers Mimic, an open source text to speech engine, as a part of its open source voice assistant. Mimic allows developers to create custom voices and can be used as a standalone TTS tool.

5. Mozilla’s TTS

Built with Python, Mozilla’s TTS offers a unique combination of traditional signal processing techniques with advanced machine learning models, providing high-quality speech output. It supports GPU acceleration, making it a suitable choice for real-time applications.

6. eSpeak

An incredibly compact open source speech synthesizer compatible with Windows, Linux, and MacOS. eSpeak supports several languages, including English and Russian, and it can be employed through command line or a simple API.

7. Flite (Festival Lite)

Developed by Carnegie Mellon University (CMU), Flite is a lightweight and versatile speech synthesis engine. It’s designed to work on embedded systems and large servers alike.

8. Tacotron 2 (by NVIDIA)

Although not an engine per se, Tacotron 2 is a neural network model architecture for generating natural speech. Open-source implementations of Tacotron 2 are available, and it has inspired many developments in speech synthesis technology. This system allows users to synthesize speech using raw transcripts without any additional prosody information.


MBROLA, an acronym for Multi-Band Resynthesis OverLap Add, is another prominent open-source TTS engine renowned for its wide language support. It caters to a multitude of spoken languages, making it an invaluable tool for projects with diverse linguistic requirements.

10. Kaldi

One of the most useful open-source TTS converting models is Kaldi. It has an effective toolkit, making speech recognition effective. The code is written in C++, making it suitable for every programmer as this is the basic language.

Applications And Use Cases Of TTS In The Field Of Business

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Customer Service Automation

Businesses benefit from leveraging Open Source Text to Speech in customer service automation. TTS technology can be used to automate customer service interactions, such as answering frequently asked questions, providing account information, or guiding users through troubleshooting processes. TTS-powered virtual assistants or chatbots can enhance efficiency, reduce wait times, and improve customer satisfaction.

Accessibility Features

Incorporating TTS functionality into digital platforms, such as websites, mobile apps, or software applications, can significantly improve accessibility for individuals with visual impairments or reading difficulties. By providing audio alternatives to text-based content, businesses ensure inclusivity and compliance with accessibility standards, thus fostering a more inclusive environment.

Multilingual Communication

The use of TTS technology enables businesses to effectively deliver multilingual communications to a diverse audience. By converting written content into spoken language, organizations can overcome language barriers, reach international markets, and enhance communication with non-native speakers or multicultural audiences.

Audio Content Creation

Leveraging Open Source Text to Speech technology, businesses can create audio content for various purposes, such as podcasts, audiobooks, training materials, or marketing campaigns. This offers businesses a way to transform written content into engaging audio formats quickly and cost-effectively, expanding their content distribution channels and audience reach.

Interactive Voice Response (IVR) Systems

TTS technology plays a crucial role in IVR systems used for automated phone-based interactions, such as customer inquiries, appointment scheduling, or product orders. By converting text prompts into spoken messages, businesses can deliver seamless and intuitive user experiences, streamline call routing processes, and improve overall operational efficiency.

Limitations Of Using Open Source TTS Models

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Not Entirely Cost Free

Open-source models, while providing valuable resources to users, may not always be entirely free of cost. Users often need to bear expenses related to hosting and server usage, especially when dealing with large or resource-intensive data sets.

Lack of Support

Open source models may not come with official support channels or dedicated customer support teams. If you encounter issues or need assistance, you might have to rely on community forums or the goodwill of volunteers, which can be less reliable than commercial support.

Limited Documentation

Some open source models may have incomplete or poorly maintained documentation. This can make it difficult for developers to understand how to use the model effectively, leading to frustration and wasted time.

Security Concerns

Security vulnerabilities can exist in open source models, and it may take longer for these issues to be addressed compared to commercially supported models. Users of open source models may need to actively monitor for security updates and patches.

Scalability and Performance

Open source models may not be as optimized for performance and scalability as commercial models. If your application requires high performance or needs to handle a large number of requests, you may need to invest more time in optimization.

Open-source licenses vary in terms of usage rights, distribution requirements, and legal obligations. Users must carefully review license agreements and ensure compliance with applicable regulations and restrictions.

Try Unreal Speech for Free Today — Affordably and Scalably Convert Text into Natural-Sounding Speech with Our Text-to-Speech API

Unreal Speech offers a low-cost, highly scalable text-to-speech API with natural-sounding AI voices, making it the cheapest and most high-quality solution in the market. We can help you cut your text-to-speech costs by up to 90%. Our super-fast, low-latency API provides human-like AI voices with the option for per-word timestamps.

With our simple, easy-to-use API, you can give your LLM a voice with ease and offer this functionality at scale. If you are looking for cheap, scalable, realistic TTS to incorporate into your products, try our text-to-speech API for free today. Convert text into natural-sounding speech at an affordable and scalable price.