By default, eflite uses the lower-quality "8 KHz" voice. If one specifies --with-vox=cmu_us_kal16 during the configure phase, it will use the higher-quality "16 KHz" voice that I prefer. The attached patch adds a new local USE flag: 16k_voice, allowing the user to select amongst the two voices. 16k_voice is enabled by default.
Created attachment 205477 [details] 16k_voice.diff
This has been fixed in portage. Thanks much for the patch. :-)