Switch between Audio Only to Audio Video Variants or vice versa in HLS

For m3u8 master playlists containing Both audio only and Audio Variants , i do not notice the switch between AudioOnly to AV or ViceVersa when the bandwidth is throttled.

example:
The below playlist has both Audio only and AV playlists.

playertest.longtailvideo.com/adaptive/oceans_aes/oceans_aes.m3u8
```
#EXTM3U
#EXT-X-VERSION:1
## Created with Unified Streaming Platform(version=1.6.7)

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=319060,CODECS="mp4a.40.2,avc1.66.30",RESOLUTION=304x128
oceans_aes-audio=65000-video=236000.m3u8

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=461100,CODECS="mp4a.40.2,avc1.66.30",RESOLUTION=384x160
oceans_aes-audio=65000-video=370000.m3u8

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=674160,CODECS="mp4a.40.2,avc1.66.30",RESOLUTION=544x224
oceans_aes-audio=65000-video=571000.m3u8

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=999580,CODECS="mp4a.40.2,avc1.66.30",RESOLUTION=736x304
oceans_aes-audio=65000-video=878000.m3u8

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1489300,CODECS="mp4a.40.2,avc1.66.30",RESOLUTION=960x400
oceans_aes-audio=65000-video=1340000.m3u8

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2233420,CODECS="mp4a.40.2,avc1.66.31",RESOLUTION=1264x528
oceans_aes-audio=65000-video=2042000.m3u8

#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=68900,CODECS="mp4a.40.2"
oceans_aes-audio=65000.m3u8

```
When the bandwidth is throttled to less than 65000 , the player should play back Audio only content . And later shift back to AV when the bandwidth increases.