DISTANCE COMMUNICATION (optical / visual or auditory): It is one in which the sender and the receiver are at points of separation where the sound of the voice is not possible to perceive effectively nor the gestures of the body.

DRUM LANGUAGE: Widely used in Africa, South America, Southeast Asia, and the South Seas. In this language, sounds are emitted through drums, whose coding consists of pitch height and rhythm.

DRUM: Percussive musical instrument, its box can be cylindrical or similar to a cone and there are different sizes. The upper part is covered with a stretched leather or plastic membrane. It is played with drumsticks, the hands, or a mace (mallet).

ELEMENT: In the case of communications, the element can be a component of nature, such is the case of fire that emits light and heat, for example. The air element that when traveling at very high speeds transmits/emits a sound.

EMITTER: It is that element, object, matter, being, person or thing that transmits or emits a signal, be it sound, visual, tactile.

HELIOGRAPH: It is a device that uses light and its reflection property using a moving mirror producing short or long flashes, in groups or separately, whoever uses it controls that at will to create letters, words or codes.

HORN (Trumpet): Wind musical instrument, conical in shape and can have intermediate forms that form a thread that modify the sound, it is blown through a mouthpiece, they usually have some buttons to release the air at different times and control the tones of the sound.

LENS: It is a piece of glass that is almost always circular, with some of its faces concave or convex, used in optical instruments.

LIGHT: It is a form of energy. It illuminates and makes things visible. It propagates through particles called photons. Sunlight is known as natural light.

LIGHTHOUSE: Tower in which from the top there is a light and this serves as a guide for boats. One of the oldest is the lighthouse of Alexandria, which is not certain if it really had light or was just a very tall tower that could be seen in the distance.

MIRROR: Piece of glass coated with alloy paint that allows a silver tone on one of its sides, which produces a reflective surface between the glass and the paint.

OPTICAL TELEGRAPH (Wooden towers): They were devices for remote communication, using possible positions of the wooden arms that were attached to a mast or base. The pioneer in this was the French Claude Chappe.

RECEPTOR: It is that element, object, material, person or thing that receives a sound, visual or tactile signal and interprets it.

SMOKE SIGNALS: They were generated with a campfire and a canvas that contained the smoke being released in periods of time that caused the fumaroles to form symbols of greater or lesser size, in turn the spacing in time generated a code. Tribes that knew the code could interpret it. They were common in surveillance posts called Watchtowers. Depending on the content of the bonfire (wet or dry branches, leaves, etc.) the color and shape of the signal varied.

SOUND: Vibrations that travel through an elastic medium such as air and produce a special impression on the ear, skin or internal organs according to the intensity of the emitted wave. Let’s not forget that the deaf perceive music by vibrations to the touch (in addition to visual support).