This is the same typo as reported in [1] and fixed in [2] in `client.conf.in`.
I did `git grep "values a commented"` and did not get anymore hits.
[1] http://pulseaudio.org/ticket/783
[2] http://git.0pointer.de/?p=pulseaudio.git;a=commit;h=
ea8927f1d47be101a1f64b2f87fd6e527ff76dbe
# USA.
## Configuration file for PulseAudio clients. See pulse-client.conf(5) for
-## more information. Default values a commented out. Use either ; or # for
+## more information. Default values are commented out. Use either ; or # for
## commenting.
; default-sink =