Mimicking sounds gives you a great start in learning a new language. Students will naturally follow the pitch of a Chinese word when asked to repeat it straight away– but to reproduce the exact sound in the correct tone a few minutes later usually needs further explanation.
Mandarin has 4 distinct tones plus a neutral tone with no emphasis. See if you can hear the direction of the pitch in each sound. Is it: High and level (1st tone), rising (2nd), falling and rising (3rd), or falling (4th)? Good tones make a great impression – have a go!