You can't directly edit files in /sys or /proc. The easiest way to change the pronounciation of a character is to use the speakupconf utility. First, as root, run "speakupconf save." Then, make your changes under /etcc/speakup/i18n. Last, run "speakupconf load." This will apply your changes. Make an entry in one of your scripts to run "speakupconf load" at boot to restore your customizations at startup.
