Sounds similar to "b" as in "boy", but voiceless. Strictly speaking, it is more like the unaspirated "p" in words like "spoon".

Sounds like "p" as in "poke".

Sounds like "m" as in "mother".

Sounds like "a" as in "palm".

Sounds like "ee" as in "bee" or "y" as in "yeast".

Single-syllable audio courtesy of the AllSet Learning Chinese Pronunciation Wiki, used with permission.

HSK word audio courtesy of Audio-cmn. (CC BY-SA 3.0)