Piss Pronouncing Worms

I know I'm a pedant but something that really frustrates me is hearing mispronounced words, for example "fus-trated" instead of "frustrated". Listen to what I've recorded on my phone, two sounds I hear most days on the commute to work and when I'm on my break. Can you guess where I recorded these two sounds and which phrase they have in common which is mispronounced?