Hi FryingMan - I started out with all night ( 8 hour sleep cycle tract ). The first night i done this I had a good stable LD but I srarted hearing the tone within my LD and it became anoying. I naturaly wake up after 4-5 hours, so I started listing when going back to bed. Its very helpful for WILDs because the frequency is progressive starting out at the relaxing but alert state to the hypnagogic state and finaly to the dream state. It dosent just knock you out so you dont loose the oppertunity for a WILD.
IsochronicBeats guy has a guide that i stumbled on
http://www.dreamviews.com/lucid-aids...nic-tones.html