Re: Ackerman ~vs~ Ockerman any info?

My grandmother's name was Ockerman and as far back as I have done research , around 1780,her ancestor's spelled their name Ockerman, even though I have found it misspelled a few times as Ackerman, Aukerman, Ocherman, Occerman, Okkerman, etc. I haven't found anything earlier on my line and am wondering about the spelling used.