I am in need of help as I've given myself quite the headache. I apologise for the forthcoming barrage of words.

I'm designing a study looking at the effects of hormone cycles on dichotic listening. In particular, looking at voice-onset-time (VOT) and correct responses over two sessions.

It will be a repeated measures design but much more than that I'm a bit stuck, so here goes.

Let's say I have a single cohort of participants taking a dichotic listening test twice (different phases of the menstrual cycle [session 1 and 2, one high hormone levels, one low hormone levels], stimuli-order different in each session) and I capture how many correct responses they have from each ear (LE and RE).

So here, the session (test sat within a particular time frame/phase of the menstrual cycle) is the independent variable as the hormones are the changing factor, and correct responses in LE and RE are what change.

First, I need to compare if the phase of the cycle (session 1 or 2) has an effect on the number of correct responses in both ears (I'm looking, initially, for a change in right-ear-advantage [REA, higher frequency of correct responses in RE]). Am I right in thinking that this would mean I need to treat the correct responses in each ear as separate dependent variables?

So 1 IV of 2 levels and 2 DV:

Mean of correct responses in LE-session1 vs mean LE-session2

Mean of correct responses in RE-session1 vs mean RE-session2

If this is the case, which test is best to use on this part? I thought a paired t-test or one-way ANOVA, however, as this is not the main focus of the study, I may perform this test post-hoc. So I'm not certain on which test to use at this phase of analysis.

The main factor is voice-onset-time (VOT). VOT will work as 4 categories short-short (SS, where both ears receive a short onset-time syllable), long-long (LL), short-long (SL, left ear short and right ear long etc), and long-short (LS). I'm expecting that SL and LS will favour correct responses in the ear with the long syllable (so SL will likely yield a correct response in the RE etc). So here, is the independent variable the VOT category and the correct responses in each ear the dependent variables? At least within a single session? But what about across both sessions?

So do I have 2 levels for the independent variable (sessions) and 4 dependent variables (correct responses within each VOT category) to examine? Is the paired t-test still appropriate for this, or a one-way repeated measures ANOVA? Or, am I on the wrong track and, by introducing the VOT categories, am I introducing a second IV, in which case I need to treat the sessions as independent groups and use a factorial ANOVA?

Finally, and I hesitate to ask this...what if I went completely insane and wanted to introduce a second cohort, of women using oral contraceptives, into the study and look at all of the above across both groups? Boom, my brain just exploded out of my ear.

Please help, I want to remain loving statistics for as long as I can.

Yours in perpetual confusion,

Agi