All Ears for Type 'n Talk by Gordon Mc Comb,
published in Creative Computing year ? page 148-152
- A Few Words About Voice synthesis
- There are three major ways to give your computer a voice. One
system, pioneered by Texas Instruments, is called Linear Predictive
Coding (LPC) where an announcer speaks into a microphone connec ted to a
computer. The computer digitizes and condenses the speech and stores it
in memory. That memory can be duplicated and inserted in a finished
product. In this way, calculators, toys and other electronic devices can
be given voices-but can only speak those words originally recorded.
Words can be combined to create complete phrases, such as "six times six
equals thirty-six." Each word is recorded separately. A small computer
inside the device picks out the proper sequence of words and strings
- Another method used by many computer hobbyists is similar to
LPC, but allows the user to speak into a microphone and digitize his own
voice. His voice is then "recorded" in memory, and recalled from the
computer at will. Super Talker from Mountain Computer provides this type
of speech capability for the Apple.
- Phoneme-based synthesis is perhaps the truest form of voice
synthesis. It creates words by imitating the sounds produced by the
human vocal tract. In this way, words, phrases and even singing can be
produced without the need to prerecord or digitize speech. One such unit
was built for the Radio Shack TRS-80. However, it takes several hours
to input a page or two of text even for the most experienced operator.
The first synthesizers of this kind were built by Bell Laboratories in
the 50's. (The first working model is featured on the Philadetphia
Computer Music Festival LP record; $6 from Creative Computing.) Later,
less elaborate commercial versions of this type of synthesizer were
shown widely in the early 70's, however, all suffered from a lack of
inflection. This gave them a decided Scandinavian or Eastern European
accent and did not contribute to their widespread acceptance.
Text-to-speech synthesis. still in its infancy, eliminates the tedious
programming of the phoneme-based synthesizer. Text is typed into a
computer and is translated by a built-in language interpreter. The
translator has been programmed to correct for the majority of
pronunciation variances inherent in our language.-DKA
- For years, computer hobbyists have seen voice synthesis as a distant
fantasy-OK for comic books and novels, but too complex and expensive
for the home computer den.
But that was yesterday!
Today, direct text-to-speech voice systems enable the home computer user
to type in plain English, and the synthesizer automatically converts
the written words into intelligible speech. Sure, this technology has
been around for a while, but not at $345!
Votrax, an old and reliable name in voice synthesis, recently announced a
product called Type 'n Talk. Type 'n Talk works with any computer and
any language, has an unlimited vocabulary, is RS-232C serial interface
compatible, and extremely easy to use.
Let's see what else Type 'n Talk has to say for itself.
- An Inside Look
It all starts at your computer or terminal. Information, in the form of
ASCII characters is sent through an RS-232C serial
interface and into Type 'n Talk (TNT). This information is fed through
very quickly - faster than the synthesizer could say the words. So a
buffer has been inserted at the input to collect the information so it
can be slowly dispersed as the words
are spoken (your printer works in a similar fashion).
From the buffer, the data is sent to a text-to-speech translator, that
decides how the words you typed will be pronounced. From the translator,
the information is sent to a voice synthesis chip. This chip creates a
series of hissing, pocking, clicking, humming and other strange sounds
that combine to form human speech. These sounds are sent through an
internal amplifier and then to your speaker.
No special hardware modifications or devices are required to connect TNT
to your computer system. However, you do need a standard RS-232C serial
interface and cable.
Up to eight TNTs can be connected to one computer system, and each can
be independently addressed. This is particularly helpful in the
You must make two other connections to complete your TNT set up: one for
power supply cable (included) and the other for the speaker connection.
You can connect TNT to any 8-ohm speaker or wire it into your hi-fi if
the on-board 1-watt amp isn't strong enough for your needs (TNT does not
have an internal speaker).
You must also select the baud rate. A series of small switches on the
back of TNT controls the rate from 75 to 9600 baud. The data buffer
built into TNT is capable of holding 750 bytes, or about one minute of
speech. At 9600 baud, this buffer takes less than one second to fill. So
while TNT is speaking, your computer is free to do other tasks.
- System Ready
When everything is properly connected, Type 'n Talk announces "system
ready." Adjust the volume control to a comfortable listening level. The
frequency control changes the speed of the voice.
On computers that don't have a built-in serial interface, you'll need to
instruct the computer on where to send the information so it'll get to
TNT. Generally, information transfers to Type 'n Talk can be
accomplished with the same commands and software used to send data to a
terminal, printer or tape drive. TNT's instruction manual gives a few
insights on hooking it into your computer.
Many of your programs can be run "as is," others you may want to modify
slightly to make better use of the voice system. Whenever there is a
PRINT statement, TNT can be made to speak the text. You can also modify
your program so it will speak some of the statements, and print out the
rest. Any combination is possible.
Audible speech is generated by the letters A through Z and numerals 0
through 9 only. Characters such as %, @, &, ( and so on) have either
no effect or produce periods of silence.
Capital letters are treated in two different manners. If only the first
letter of a word is capitalized, then TNT will pronounce the word in the
usual fashion. But if the first two (or more) letters are caps TNT will
spell out the word, letter by letter.
For example: The words T-H-E and T-E-D are pronounced tee-aych-ee and
tee-ee-dee. The words and t-h-e and T-e-d are p