Is an overview available of general indicators or signs that can indicate the presence of eavesdropping devices?
This question cannot be answered unequivocally, and should in fact be approached with some caution. Generally speaking, professionally installed eavesdropping devices do not reveal their presence through any form of interference. This includes any form of clicking, hiss, other audible conversations or complete silence when a telephone call is answered. The cause of technical disruptions can usually be traced to improperly configured (company) telephone switchboards or improperly installed cabling, rather than to eavesdropping equipment. Indications of the presence of eavesdropping devices should be sought more in unusual events, incidents or behavior on the part of conversation partners or one’s own employees.
