Mac Vocalizer
Speech Announcements for PREDICT on Mac OS X

Must Be Art > Software > Mac Vocalizer


PREDICT is a satellite tracking program (what's that?) designed primarily to run on Linux, but portable enough to run on Mac OS X (thanks to the Unix underpinnings of OS X). One feature of PREDICT that is not very portable is the separate vocalizer utility, which is invoked by the main PREDICT program in order to "speak" announcements about the satellite's azimuth and elevation. The program supplied with PREDICT uses sound facilities that are not implemented in the same way on Mac OS X.

When Mac Vocalizer was first implemented, the Linux vocalizer used home-recorded voice files and spoke individual digits (“123” as “one two three”), whereas Mac Vocalizer took advantage of the number speaking algorithms in the Macintosh speech synthesizer to render the numbers naturally (“one hundred and twenty-three”). This was a big improvement. As of PREDICT version 2.2.2, the Linux vocalizer has been improved to use nice synthesized voice files (better than the Mac's) and natural number rendering.

As a result of this improvement, a port of the Linux vocalizer might now make more sense than Mac Vocalizer. In the meantime, this update (1.1.0) of Mac Vocalizer supports the new speeches implemented in PREDICT 2.2.2.

System Requirements

Mac Vocalizer was built on Mac OS X 10.2.6, and has only been tested on that system. However, as far as I know it should work on any Mac OS X system.

Naturally, you will need sound output capability and speakers in order to hear the announcements. Type some text into TextEdit and check that the Edit, Speech, Start Speaking menu item works.



Current Status

Second release. No current development plans, except that I might try a direct port of PREDICT's vocalizer to replace this program. The current released version of Mac Vocalizer is 1.1.0, released July 25, 2003.

Works under Mac OS X 10.4 Tiger, and has significantly less delay than under previous versions of Mac OS X.


Known Bugs


If you get a message like this:
## Component Manager: attempting to find symbols in a component alias of type (regR/carP/x!bt)
when vocalizer is invoked, the problem is at the system level. Look in the directory /Library/QuickTime and remove the item named Toast Video CD Support.qtx and see if that helps. Don't ask me to explain why.


Mac Vocalizer is released under the GNU General Public License, Version 2.

Source Code

Source code in C for Carbon is included, along with a Project Builder project from the December 2002 Developer Tools release.


MacVocalizer.html - user manual (HTML, 7K)


Mac Vocalizer 1.1.0 (.tar.gz file, 14K)

See Also

PREDICT web page.

Copyright 2002-2005 Paul Williamson. Comments to