Free & Paid Speech Synthesis Engines: Which Software Uses What?

Currently, many text-to-speech software programs have been released.

However, when listening to the voices of text-to-speech software, you might think, "Wait, isn't this tone of voice the same as other software?"

In fact, text-to-speech software requires a base speech synthesis engine.

Therefore, even if the software names are different, if the speech synthesis engine is the same, the tone of voice will be the same.

This time, we will introduce speech synthesis engines that can be used for free and those that can be used for a fee.

There is also information that might make you think, "Ah, so that software was using this synthesis engine!"

Please take a look!

Speech Synthesis Engines That Can Be Used for Free

Free text-to-speech software mainly uses the following:

• AquesTalk (AquesTalk)
• Open JTalk (Open JTalk)

These speech synthesis libraries and speech engines are used.

AquesTalk (AquesTalk)

Developed by AQUEST Co., Ltd., AquesTalk is known as "Yukkuri Voice" or "Bouyomi Voice."

All software that can read aloud in the tone commonly known as "Yukkuri" adopts "AquesTalk."

Representative examples include Bouyomi-chan and SofTalk.

Because synthetic speech can be easily created from text, it is used in various situations from personal use to commercial products.
In addition to being used as the base for SofTalk, Bouyomi-chan, etc., it is also used for sampling in the default voice of UTAU. Furthermore, it is used as guidance voices for household appliances such as telephones.

AquesTalk was first released on May 25, 2006. The development period was said to be just under two years. (AquesTalk Release exit)
The sound source is created by manually manipulating parameters rather than by recording; it is truly a pure synthetic voice with no "person inside."

In January 2010, the successor version, AquesTalk2 exit, was announced.
It supports a wide range of platforms, including smartphones such as Windows, Mac OS X, WinCE, iPhone, and Android. Recently, an independent microchip (hardware) called AquesTalk pico has also appeared.

Source: Nico Nico Pedia

Because API usage licenses and development libraries are provided, it can be used for various purposes if you have programming skills.

Let's check the company website for details.

AquesTalk

We also explain Yukkuri Voice in this article.

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Open JTalk (Open JTalk)

Open JTalk is a Japanese text-to-speech synthesis system developed at the Tokuda/Lee Laboratory of the Nagoya Institute of Technology.

It is open source, distributed under the Modified BSD License.

"Open JTalk" is used in Textalk. You might feel like "I've heard this before" once you listen to it.

Open JTalk

Speech Synthesis Engines That Can Be Used for a Fee

Famous paid speech synthesis engines include:

• IBM: Watson Text to Speech
• Google: Text to Speech
• Amazon: Polly
• Microsoft: SAPI5

There are many attractive plans, such as being free for up to tens of thousands of characters.

Demos of the above paid speech synthesis engines are provided on their websites, where you can play them and hear the audio.

Speech Synthesis Engines Have a High Level of Difficulty

This time, we introduced speech synthesis engines.

By using a speech synthesis engine, you can create your own text-to-speech software or finish it as text-to-speech software customized to your preference.

However, if you actually try to use one, it is difficult to set up unless you can program, as they are provided as APIs.

API is an abbreviation for "Application Programming Interface," and it refers to "programs specialized in a certain function that can be shared" or "a mechanism for sharing software functions." If frequently used functions are provided as APIs, there is no need to build a program from scratch. You can proceed with development efficiently by using APIs as needed.

In the case of a Web API, the program is published on the web and utilized by calling it from the outside. Web APIs are published in various fields, and many Web APIs are available for free.

For example, if you can obtain the latest information from another company's site via an API, you can add new functions to your own website or app to improve the service. Since the level required for smartphone apps has increased in recent years, it has become common to use Web APIs in app development.

Source: internet academy

Companies that provide paid versions of text-to-speech software either develop their own speech synthesis engines or use the paid speech synthesis engines introduced here.

"Wait, why not just make a speech synthesis engine yourself?"

You might think so, but it is not an easy task.

It would be a task requiring many researchers, developers, money, and a very difficult process.

At the very least, it is difficult for an individual and is not realistic unless you have the scale of a company or research institution.

Therefore, if you find using an API difficult, using paid text-to-speech software is more intuitive and easier to handle.

Many types of text-to-speech software have been released, ranging from free to paid.

I am sure you will find your favorite software.

We have summarized them in detail in this article, so please check it out!

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I hope this article is helpful to you.

Well then, I look forward to seeing you again.