I have my suspicions this could be something to do with a problem that is 
causing audio output to my headset to go completely silent on random 
occaisions (usually a 'killall -USR2 btsco' fixes it, but in extreme cases I 
have had to unload the module and reload it).

From dmesg, repeated nearly 1500 times:
snd-bt-sco: Shift problem detected! Fixing to 1.
snd-bt-sco: Shift problem detected! Fixing to 0.

And occaisionally this message (or some variation on the number of files):
snd-bt-sco: file_count is 4 (expected 3)

Headset is a Sony Ericsson HBH-IV835
        BD Address:  00:18:13:7e:bc:7a
        Device Name: HBH-IV835
        LMP Version: 2.0 (0x3) LMP Subversion: 0xe1b
        Manufacturer: Texas Instruments Inc. (13)
        Features: 0xff 0xfd 0x29 0x78 0x18 0x18 0x00 0x80
                <3-slot packets> <5-slot packets> <encryption> <slot offset>
                <timing accuracy> <role switch> <hold mode> <sniff mode>
                <park state> <channel quality> <SCO link> <HV2 packets>
                <HV3 packets> <u-law log> <A-law log> <CVSD> <transparent SCO>
                <enhanced iscan> <interlaced iscan> <interlaced pscan>
                <inquiry with RSSI> <AFH cap. slave> <AFH class. slave>
                <AFH cap. master> <AFH class. master> <extended features>

Adapter is 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
hci0:   Type: USB
        BD Address: 00:02:72:B0:36:D7 ACL MTU: 192:8 SCO MTU: 64:8
        UP RUNNING PSCAN ISCAN
        RX bytes:21511295 acl:351 sco:420012 events:8971 errors:0
        TX bytes:21398439 acl:305 sco:418646 commands:7868 errors:0
        Features: 0xff 0xff 0x0f 0x00 0x00 0x00 0x00 0x00
        Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3
        Link policy: RSWITCH HOLD SNIFF PARK
        Link mode: SLAVE ACCEPT
        Name: 'insanity'
        Class: 0x3e0100
        Service Classes: Networking, Rendering, Capturing, Object Transfer, 
Audio
        Device Class: Computer, Uncategorized
        HCI Ver: 1.1 (0x1) HCI Rev: 0x110 LMP Ver: 1.1 (0x1) LMP Subver: 0x110
        Manufacturer: Cambridge Silicon Radio (10)

Since 99% of the time there is no problem that needs to be solved, is there a 
simple way to just reduce the verbosity of output to the system log?

--Thomas