Learning to Beatbox? Here is the Human Beatbox Sound Archive Entry for the Inward Basic Lip Kick.
Name: Inward Basic Lip Kick
Family: Lip Based Kicks (B)
Description: This sound is made by creating suction behind closed lips, then pulling in a burst of air. It is similar to the sound made by a "b" or "p" in English, but is made by inward air motion. There are two main variations in how this sound is made. It can be ingressive, meaning that uses airflow into the lungs, or it can be an implosive, meaning that does not use airflow from the lungs, it simply pulls air into the mouth using suction.
Other Links: About the Human Beatbox Archives and Notation System