This translation contains some new information. It also corroborates other details that were posted to the ENIGMA 2000 group.
Here's her report. Italicized numbers are for my own footnotes.
I just listened to the audio. It sounds like they were making an announcement using coding. And I don't know exactly where it comes from but it's a Northern Vietnamese voice. [1] Here's the translation:
Sơn Ca gọi Hải Đăng năm hai năm ba (x9)
"Son Ca [2] is calling Hai Dang [3] 5253"
Số điện sông năm tám hai hai (x3)
"Phone number: 05822" [4]
Số nhóm bảy một (x3)
"Number of groups: 71" [5]
Ngày [?] ba chín số một trong (once)
"Date: 3/9/2010" [6]
Nội dung của đầu (x3)
"Content's beginning:"
[message in 5F groups, no repeat] 05711 21249 05433 56985.....12289
Sơn Ca gọi Hải Đăng năm năm năm eigh
"Son Ca is calling Hai Dang 5558." [7]
[1] The translator used by an ENIGMA 2000 member also said the voice was in a Northern dialect.
[2] Possibilities:
Đảo Sơn Ca, an island in the South China Sea.
Generic for Cay or Key (small island in a group).
Popular Vietnamese record label.
Someone's name, perhaps a singer.
[3] Google translates Hải Đăng as "Lighthouse."
[4] She translated it as "phone number." A colloquialism? Or is it really a standard "numbers" callup signifying a group or message router?
[5] There are indeed 71 groups in the message. I counted. Twice.
[6] This transmission was recorded on March 18, 2010. This is a further indicator that recorded broadcasts are repeated on subsequent days until the message changes.
[7] You have to listen carefully, and the number at the end really is different than the one at the beginning. I wonder if this is true for other broadcasts.