So, for example, if I was angry and had to hide it, which I often did, being very adept at concealing how I really felt, then the voice would sound frustrated.
즉 예를 들어,  화가 났지만 숨겨야 할 때 종종 그랬던 것처럼 매우 능숙하게 실제로 어떻게 느끼는지를 숨겼지만 그 목소리는 화난 것처럼 들렸어요.