Echo II (expansion card)
{{about|the speech synthesizer card|other uses|Echo II (disambiguation)}}
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The Echo II is a plug-in expansion card, speech synthesizer card for the Apple II and Apple IIe personal computers that allow applications to use speech synthesis.{{Cite web |title=Learning With Computers: The Computer Speaks, But Will It Listen? |url=https://www.atarimagazines.com/compute/issue50/261_1_Learning_With_Computers.php |access-date=2023-03-19 |website=www.atarimagazines.com}} The Echo II provides a speaker/headphones jack on board, with a physical volume control adjustment.
The Echo II software can synthesize either unlimited text-to-speech using stitched phonemes, or play back raw LPC data for specific words, with resulting higher speech quality.
LPC (linear predictive coding) is the speech synthesis technology used, which allowed applications to encode speech data in a compact form. The Echo II uses the TMS 5220 LPC Speech Chip which was popular in other speech synthesizers.
References
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External links
- [http://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Interface%20Cards/Speech/Street%20Echo%20II/ Mirrors.apple2.org.za]
- [http://personalpages.tds.net/~ti51/new49.htm Echo II and other Street Electronics speech cards] {{Webarchive|url=https://web.archive.org/web/20090613052023/http://personalpages.tds.net/~ti51/new49.htm |date=2009-06-13 }}
- [https://web.archive.org/web/20090613054331/http://apple2history.org/museum/peripherals/echo.html Apple history page showing newer echo 2 card]
{{Speech synthesis}}