To help the OP... It is a USB device.
[ 598.260000] usb 2-2: new full speed USB device using uhci_hcd and address 4
[ 598.440000] usb 2-2: configuration #1 chosen from 1 choice
Bus 002 Device 004: ID 07b4:020d Olympus Optical Co., Ltd Digital Voice Recorder VN-240PC
T: Bus=02 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 4 Spd=12 MxCh= 0
D: Ver= 1.10 Cls=ff(vend.) Sub=ff Prot=ff MxPS= 8 #Cfgs= 1
P: Vendor=07b4 ProdID=020d Rev= 1.00
S: Manufacturer=OLYMPUS IMAGING CORP.
S: Product=DIGITAL VOICE RECORDER
C:* #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=100mA
I:* If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
E: Ad=81(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms
E: Ad=02(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms
E: Ad=83(I) Atr=03(Int.) MxPS= 8 Ivl=50ms
I was wrong... there is a linux driver but it looks like it only works in extra high quality mode for this particular device:
Might want to email the project owner and see if he has any ideas. However without being able to access the flash memory directly I do not know of any way to recover lost data.