Sorry your computer doesn't play the sounds. Clicks do occur in English, they're just not phonemes like they are in Xhosa. We have the dental (alveolar) click which is usually represented by the interjection tsk when it is pronounced as a click rather than its spelling pronunciation as /'tIsk/. The lateral click in the ethnonym Xhosa is closer to our click in our giddyup sound: made closer to the sides of the mouth. This sound doesn't have a transcription that I'm aware of, but occurs twice or thrice after one says giddyup to a horse. Perhaps the most familiar click in English is the kissing sound, or bilabial click.

Ceci n'est pas un seing.