Today, speech synthesizers used in stationary computer systems or mobile devices no longer seem unusual. Technology has stepped far ahead and made it possible to reproduce the human voice. How it all works, where it is applied, what is the best speech synthesizer and what potential problems the user may encounter, see below.
What are speech synthesizers and where are they used?
Speech synthesizers are special programs consisting of several modules that allow you to translate text typed on the keyboard into normal human speech in the form of sound.
It would be naïve to believe that the accompanying libraries contain absolutely all the words or possible phrases recorded in studios by real people. It's just physically impossible. In addition, the phrase libraries would be of such a size that it would simply not be possible to install them even on modern large-capacity hard drives, not to mention mobile devices.
For this, a technology called Text-to-Speech (text-to-speech) was developed.
Speech synthesizers are most widely used in several areas, which include self-study of foreign languages (programs often have support for 50 languages or more), you need to hear the correct pronunciation of a word, listening to texts of books instead of reading, creating speech and vocal parts in music, their use by people with disabilities, the issuance of search queries in the form of voiced words and phrases, etc.
Varieties of programs
Depending on the area of application, all programs can be divided into two main types: standard ones that directly convert text to speech, and speech or vocal modules used in music applications.
For a more complete understanding of the picture, consider both classes, but more emphasis will still be placed on speech synthesizers in their direct purpose.
Pros and cons of simple speech apps
As for the advantages and disadvantages of programs of this type, let's look at the disadvantages first.
First of all, you need to clearly understand that a computer is a computer, which at this stage of development can synthesize human speech very approximately. In the simplest programs, problems with the placement of stress in words, reduced sound quality are often observed, and in mobile devices, increased power consumption, and sometimes unauthorized loading of speech modules.
But alsoThere are enough advantages, because many people perceive sound information much better than visual information. Ease of perception is obvious.
How do I use the speech synthesizer?
Now a few words about the basic principles of using programs of this type. You can install a speech synthesizer of any type without any problems. In stationary systems, a standard installer is used, where the main task will be to select supported language modules. For mobile devices, the installation file can be downloaded from an official store or store like Google Play or AppStore, after which the application is installed automatically.
As a rule, at the first start, you do not need to make any settings other than setting the default language. True, sometimes the program may offer to select the sound quality (in the standard version, which is used everywhere, the sampling rate is 4410 Hz, the depth is 16 bits and the bit rate is 128 kbps). In mobile devices, these figures are lower. Nevertheless, a certain voice is taken as the basis. Using the standard pronunciation template, applying filters and equalizers, this sound is achieved.
In use, you can choose several options for translating text: entering text manually, voicing already existing text from a file, integration into other applications (for example, web browsers) with activation of search results or reading text content on online pages. It is enough to choose the desired course of action, the language and the voice in which all this will be pronounced. Many programshave several varieties of voices: both male and female. The start button is usually used to activate the playback process.
If we talk about how to turn off the speech synthesizer, there may be several options. In the simplest case, the playback stop button in the program itself is used. In the case of browser integration, deactivation is performed in the extension settings or by completely removing the plugin. But with mobile devices, despite the direct shutdown, there may be problems, which will be discussed separately.
In music programs, settings and typing are much more difficult. For example, the FL Studio application has its own speech module, in which you can select several types of voices, change the tone settings, playback speed, etc. The “_” character is used to stress before a syllable. But even such a synthesizer is only suitable for creating robotic voices.
But Yamaha's Vocaloid package belongs to the professional type. The Text-to-Speech technology is implemented here to the fullest extent. In the settings, in addition to the standard parameters, you can set articulation, glissando, use libraries with vocals from professional performers, compose words and phrases, adjusting them to notes, and a whole lot more. It is not surprising that a package with only one vocal takes up about 4 GB or more in the installation distribution, and after unpacking - twice or three times as much.
Speech synthesizers with Russian voices: a brief overview of the most popular
But let's get back to the simplest apps and look at the most popular ones.
RHVoice - according to most experts, the best speech synthesizer, which is a Russian development by Olga Yakovleva. Three voices are available in the standard version (Alexander, Irina, Elena). The settings are simple. And the application itself can be used both as a standalone SAPI5-compliant program and as a display module.
Acapela is a rather interesting application, the main feature of which is the almost perfect voice acting of the text in more than 30 languages of the world. In the regular version, however, only one voice is available (Alena).
Vocalizer is a powerful application with the female voice of Milena. Very often this program is used in call-centers. There are many settings for setting stress, volume, reading speed and installing additional dictionaries. The main difference is that the speech engine can be integrated into programs like Cool Reader, Moon+ Reader Pro or Full Screen Caller ID.
Festival is a powerful speech synthesis and recognition utility created for Linux and Mac OS X systems. The application comes with open source code and, in addition to standard language packs, even supports Finnish and Hindi.
eSpeak is a speech app that supportsover 50 languages. The main disadvantage is the saving of files with synthesized speech exclusively in the WAV format, which takes up a lot of space. But the program is cross-platform and can be used even in mobile systems.
Google Android speech synthesizer issues
When installing the "native" speech synthesizer from Google, users constantly complain that it spontaneously turns on the download of additional language modules, which can not only take quite a long period of time, but also consumes traffic.
It's very easy to get rid of this on Android systems. To do this, use the settings menu, then go to the language and voice input section, select voice search and on the offline speech recognition option, click on the cross (disable). Additionally, it is recommended to clear the application cache and restart the device. Sometimes it may be necessary to turn off notifications in the application itself.
What is the result?
Summarizing a certain result, we can say that in most cases the simplest programs are suitable for ordinary users. RHVoice is the leader in all ratings. But for musicians who want to achieve a natural sounding voice, so that the difference between live vocals and computer synthesis is not felt by ear, it is better to give preference to programs like Vocaloid, especially since many additional voice libraries are released for them, and the settings have so many possibilities that primitive applications, as they say, anddid not stand nearby.
