Low-frequency transient response is often used to detect or identify buried objects. At sufficiently low frequencies, the signal penetration in the ground is high and the air-earth interface has a negligible effect on the return response. The use of an exciting current loop also minimizes the ground conductivity effect. These properties are used to develop an efficient numerical method to compute and study the transient response of permeable objects. A few representative results for rotationally symmetric objects are presented and discussed. >