[Excerpts from online regulations]
Electronic Deer Calls
Recorded or electrically amplified calls or sounds are prohibited for the purpose of deer hunting. This would include calls or sounds imitating common deer vocalizations or noises such as grunts, snorts, bleats, and antler rattling. Non-electronic deer calls are permitted for deer hunting.

MIGRATORY GAME BIRDS
Use recordings of migratory game bird calls and sounds or electronically amplified imitations of bird calls is prohibited.

 Wild Turkey Hunting
It is illegal to bait for spring and fall turkey hunting, use recorded or electronically amplified calls, or use motorized or electronic turkey decoys. An area is considered by law to be baited for 10 days after removal of the bait. Dogs and organized drives may not be used for hunting turkeys in the spring.

Baiting/Attracting Bears
The use of any bait, scent attractants or electronic calls is prohibited for black bear hunting.

FURBEARERS
The use of artificial light and/or dogs is permitted while hunting coyote, fox, opossum, or raccoon on foot. Coyote, fox, opossum, and raccoon can be hunted with the aid of electronic calling devices. Daytime and nighttime hunting for fox is permitted during the legal harvest season for foxes except Sundays. Coyote can be hunted at night during the period specified in the furbearers seasons and bag limits chart. At all other times of the year, coyote may only be hunted during the legal daylight shooting hours.

UPLAND
The use of decoys, calls and/or recordings for hunting crows is allowed. Hunters must wear fluorescent orange when hunting upland game except crows. 

After a discussion with a CSR, FOXPRO was informed that the laws have not changed pertaining to the use of electronic calls and decoys.  They are still legal for coyote, bobcat, fox, raccoon, and crow.

[Overview]
Maryland permits the use of electronic wildlife calls for fox, coyote, raccoon, bobcat, crow and opossum. Electronic or mechanical decoys are strictly prohibited for turkeys, along with electronic wildlife calls.