Thais don't enunciate the endings of words like we do in English (not counting the Cockneys or Northerners who don't enunciate their words in English either...)
We expel a puff of air quite forcibly when saying a word like "stoppp". Thais just say "sto" and then simply close their mouths for the "p" and stop.
Now, this actually makes reading Thai relatively straight forward. There is no such thing as an 'initial' sound and a 'final' sound for each consonant letter in Thai. There is just the one sound. Less to remember...!
The only proviso is that the one sound simply isn't sounded when it's written at the end of a word. So "krab" becomes "khrab". It's not "khrap". The "b" is formed as a close-lipped "b" sound but not pronounced. Shaken but not stirred.
There are a few small exceptions. The letters for R and L (and one of the Y letters) becomes "N" at the end of a word. That's why "bill" is pronounced "bin", and "central" becomes "sentran" and "school" becomes "skhoon".
This is one of the reasons why it's best not to rely on phonetic transliteration for Thai and to learn to read right out of the gate. Otherwise confusing aspects about the Thai language start to make more sense when you can see how the word is spelled in reality.