I just talked to my wife and her Nokia headset and mine are identical 3 conductors and different phones.  I therefore suspect same for others.  Try a stereo male to RCA female  adapter and than pick off the appropriate channel for your recorder.  Parts available at radio shack.

thank you!

BRETT K WINCHESTER  PM  KD7JN   VOLUNTEER & READING SERVICES MANAGER
[log in to unmask]     http://www.icbvi.state.id.us/brochure/RADIO.HTM 
Member IAAIS International Association of Audio Information Services
IDAHO COMMISSION f/t BLIND & VISUALLY IMPAIRED - ICBVI
P O BOX 83720,    341 W WASHINGTON,    BOISE IDAHO  83720-0012
208-334-3220 ext 104 +7=voice mail after hours,                    Fax  208-334-2963