Audio quality does matter. DRM delivers!

Interesting research here from USC.
"Audio quality influences whether you believe what you hear." DRM fans already knew that!

Relay of National news broadcast using Codec2

"Relay of National news broadcast using FreeDV in SE Australia next Sunday"  
Read the article here.

A ham software application has been developed that implements the new super-efficient Codec2 audio codec. The software is called FreeDV and is freely available with the open source codec. Speech is compressed down to 1400 bit/s then modulated onto a 1100 Hz wide QPSK signal which occupies half the space of a conventional analogue SSB transmission.

We've covered alternative codecs in previous DRMNA posts. What this means is that not only can digital voice be sent and received using off the shelf equipment, but if this were implemented into DRM, a multiplexed signal with with even more voice channels would be possible. The improved intelligibility, higher compression and narrower bandwidth betters all previous voice codecs by a significant amount.

Here is an opportunity to push-the-envelope and make an even more robust and higher-utility implementation of DRM. Will it happen? We shall see. It does follow the "open source" rubric we always hear from the DRM Consortium.

Radio Exterior de España [REE] on 9630kHz

Here is a brief video of my DRM reception of REE on 20111108 at 00:30z. They are a bit overkill on the bitrate, but it sounds good.

Voice of Russia DRM transmitting with two audio streams

(UPDATED 20111022 with image from Alokesh at bottom of post)

Glenn Hauser's DX Listening Digest (also Glenn's World of Radio) featured a report from Giampiero Bernardini in Milan, Italy. He mentioned hearing Voice of Russia on 9850 kHz at 0820z on the 7th of October broadcasting in DRM with 2 audio streams. I have always thought that this is a great and innovative use of DRM. I certainly wish I had more information, but it was described as in English and Russian "DRM RUVR 1A" & "DRM RUVR 1B"

If my knowledge of DRM is correct, this could be done in CELP or HVXC using two 8 kHz or similar audio streams. This would be near the robusteness of what we are used to with RNZI broadcasting one stream of 15.48 kHz AAC+.