In electronics terms, crosstalk occurs when unwanted speech or signal noise manifests in a communication. A common example of crosstalk is hearing pieces of other people's conversations on a telephone, or picking up part of a broadcast from a different radio station when listening to a radio show. Crosstalk is caused by an inadvertent coupling of transmission media, such as radio frequencies or physical telephone wires, and technicians take steps to avoid it. The term is also used more generally to refer to incidental or unimportant conversation.

In the case of telecommunications devices connected with physical wiring, crosstalk happens whenever these wires cross. This causes a disturbance in the signal, which manifests in the ear of the listener as signal noise or fragments of speech. Insulating wiring and tightly twisting it can greatly reduce this type of crosstalk, although wiring will ultimately decay as it ages, necessitating repairs. If a consumer experiences crosstalk on a device such as a telephone, it should be reported to the phone company so that they can address the problem.

Communications which travel from place via wave signals, such as radios, can also be victims of crosstalk. Frequencies which are too close to one another can result in crosstalk, and electromagnetic interference from another source can also cause a disturbance in the signal. In communications systems such as two way radios, it is not uncommon to experience crosstalk from people who are transmitting in the same frequency. In the case of official frequencies, such as police radios, a dispatcher or central control may request that the unauthorized person using the frequency switch to another frequency.

Digital devices can also experience crosstalk due to hiccups in their mechanisms. Neighboring connections may be loose or unsound, causing crosstalk, or the system may experience a power surge or overload which causes crosstalk. Digital devices which handle high volumes of material can also overheat or generate a lot of noise in their regular operations, which will translate into crosstalk for users. Technicians attempt to maintain signal integrity so that this does not happen, but a digital system can fail under stress, just like any other system.

Generally, crosstalk or electrical interference are undesired in telecommunications. For this reason, the telecommunications industry invests time and money in reducing the probability of crosstalk on their systems. Electrical and audio engineers may choose to specialize in crosstalk so that they can obtain profitable jobs in the telecommunications industry, as there is always a need for skilled engineers to work on telecommunications systems.