With Espeak built for PulseAudio, speech interruption (e.g., cursor movement in the Orca Screen-Reader) causes PulseAudio to freeze for approx. two seconds before allowing further Espeak output.
The problem manifests _only_ when speech is interrupted.
This is probably a problem with PulseAudio integration, not with eSpeak.
You could examine the eSpeak source file: wave_pulse.cpp, or contact Gilles Casse <gcasse@oralux.org> who wrote it. But unless you can explain how eSpeak is doing something wrong, then I don't think I can do anything.