Not knowing for certain its origin I am forced to guess, but I am reasonably certain that the "be" at the end are probably silent letters. This would make the pronunciation something like Black Coom. The "oo" is likely pronounced as in Zoom.
Boyce Combe's birth name is Boyce Molyneaux Combe.
The population of Combe Martin is 2,650.
Delphine Combe was born in 1974.
Combe Miller died in 1814.
Combe Miller was born in 1745.
Lisle Combe was created in 1839.
Combe Gibbet was created in 1676.
The population of Combe Florey is 252.
Dominique Combe goes by Do.
Taylor Combe died in 1826.
Taylor Combe was born in 1774.
Monkton Combe's population is 556.