How to pronounce [b]:
Close your lips tightly and then let a little bit of airflow comes out your mouth by a sudden release of lips but with no vibration of the vocal cord. The sound of [b] is like the “b” in English word “bird”.
How to pronounce [p]:
The position of articulation is the same as that of [b] and then push the airflow forcibly out without vibration of the vocal cord. The sound of [p] is more like the “p” in English word “park”.
1. [b] [p] are bilabial plosive initials.
2. Vocal cord: [b] [p] are both voiceless.