Both native and non-native English speakers systematically devoice their final consonants in normal speech. Devoicing involves turning consonants that are supposed to be voiced (the final [b] in Bob, for example) into either a voiceless [b] (indicated by a diacritic in the transcription) or its voiceless counterpart [p]. So when the final consonant in Bob is devoiced, it will sound like "Bop." The native phonology of many non-native speakers does not include either final voiced obstruents or final consonants at all which results in the devoicing or complete deletion of final consonants by these speakers when speaking English. Turkish 1 contains a good example of devoicing.
Please call Stella. Ask her to bring these things with her from the store: Six spoons of fresh snow peas, five thick slabs of blue cheese, and maybe a snack for her brother Bob. We also need a small plastic snake and a big toy frog for the kids. She can scoop these things into three red bags, and we will go meet her Wednesday at the train station.
blue symbols = potential areas for final devoicing
red symbols = actual areas of final devoicing