Words are inadequate

It's not so much hearing it as "not hearing" where there "ought" to be something. It "sounds" like a slight pause. It's a lot easier if you try saying some words out loud and pay attention to what your throat does. When I say "apple", there's a slight contraction of the throat before the vocalization of the 'a'. As if in the absence of an initial consonant, my throat wants to return to a "home" position before vocalization. It's almost like I'm going to make a short 'i' sound, like in the word "in", but instead of actually saying 'i', I move to the 'a'.