One thing you don’t think of first before you start an audio book is how different speech sounds from the way it’s written. Take “she’d tried harder” from this week’s episode. No problem, right? Except the ‘d’ at the end of she’d rests right against the ‘t’ from tried. When spoken, it sounds exactly like “she tried harder”. What happened to the ‘d’? Trying to pronounce both of them inserts a very conspicuous break between “she’d” and “tried” which not only sounds awkward, but is also not like anyone actually talks. I don’t actually know what to do about this, but I have gotten into the habit of over-enunciating my words so I can be understood clearly.
Relevant: this SMBC comic about glottal stops in conversational American English. I don’t think Batman is a great example, as it’s easy and not uncommon to pronounce both the ‘t’ and the ‘m’, but it’s an astute observation that applies often, and Batman makes for a better punchline.