An answering service can screen out nuisance calls.
【screen】自动应答服务可以挡掉骚扰电话。
英语百科
Nuisance call
Nuisance calls encompass any type of unwanted, unsolicited, telephone call. Common types of nuisance calls include prank calls, telemarketing calls, and silent calls. Obscene phone calls and other threatening calls are criminal acts in most jurisdictions, particularly when hate crime is involved.