Mac OS X: Ask every voice found by `say -v "?"` to say the demo text. Note that `say` only returns voices for your system language.

macosx_voices_demo.py

# -*- coding: utf-8 -*-
"""
Ask every voice found by `say -v "?"` to say the demo text.
Note that `say` only returns voices for your system language.
"""
import time
from subprocess import Popen, PIPE


def say(voice, text):
    args = ["say", "-v", voice, text]
    p = Popen(args)
    p.communicate()


def iter_voices():
    args = ["say", "-v", "?"]
    p = Popen(args, stdout=PIPE)
    out, err = p.communicate()
    for line in out.splitlines():
        name_lang, demo = line.split('#')
        elacol, eman = name_lang.strip()[::-1].split(' ', 1)
        yield line, eman.strip()[::-1], elacol.strip()[::-1], demo.strip()


def demo_all():
    for line, name, locale, demo in iter_voices():
        print line
        say(name, "I'm {}.".format(name))
        time.sleep(1)
        say(name, demo)
        time.sleep(1)


if __name__ == '__main__':
    demo_all()