i think i may have been ambiguous in my phrasing and i should clarify.
i would not set timing by ear if the starting timing point is not known. in previous posts, i said that i would use a light if the dizzy had been removed and re-stabbed.
i use the ear method when (for example) i know i am at 10* and want to advance it up for winter. i could use the light and set it at 12, then 14, then 15 degrees (and so on), but i know i am at 10* and i want to advance it till i ping. so i bump it a smidge and then drive while listening for detonation - i dont know what exact number i will see detonation at so the light is not helping me. so i sometimes omit the use of the light when going from 10 to 12 to 14. i just advance it a smidge, lock it, and drive it. thing is, whether or not i use a light, i have to drive and listen for pinging - everyone should. a case in point of the timing light misleading someone is if the outer ring of the balancer has slid. one must listen - there is no magic timing number for any motor.
MusPappis, i would follow the advice of others (and myself) - if you have no clue where your timing is at, use the light. where we were all differing was largely semantics - some use a light to go from exactly 10* to exactly 14*, for example. i know i am at 10* and advance it a bit and drive it. but if i had no idea where the timing was set at (and did not have a good feel for how much rotation of the dizzy equalled how many degrees change), i would highly recommend the use of a light. i am sure you know all of this, but your post worried me a little.
the playing with it by ear is purely a 'final and fine touch' procedure that i do when i know i am really close and being finicky (from 10-15*, for example). the safe way and best way is to always use a light. im just lazy.
BTW, some of the old hot rod guys did not use a light cuz the timing was so inaccurate on a car with miles on it, nothing was too close to factory spec.
