Americans do that quite often. They use the schwa sound to represent/compress vowels.
The schwa sound is a slight uh. So America is pronounced uhMERIKuh, sounds like MERIK, then they link lots of words, so instead of BUS STOP, you will hear BUSTOP. Or instead of "I am going", You will hear, "I'm going", but the I will be compressed to an uh and liked to the m with a y sound. Iyam, "yuhM going"
Chances are that's what your cousin was doing but on a less subtle level.
The schwa sound is a slight uh. So America is pronounced uhMERIKuh, sounds like MERIK, then they link lots of words, so instead of BUS STOP, you will hear BUSTOP. Or instead of "I am going", You will hear, "I'm going", but the I will be compressed to an uh and liked to the m with a y sound. Iyam, "yuhM going"
Chances are that's what your cousin was doing but on a less subtle level.