Updated espeak packages that fix one bug are now available for Red Hat Enterprise Linux 6.
The espeak packages contain a software speech synthesizer for English and other languages. eSpeak uses a "formant synthesis" method, which allows many languages to be provided in a small size.
Previously, eSpeak manipulated the system sound volume. As a consequence, eSpeak could set the sound volume to maximum regardless of the amplitude specified. The sound volume management code has been removed from eSpeak, and now only PulseAudio manages the sound volume.
All users of espeak are advised to upgrade to these updated packages, which fix this bug.