The loud hailer is a funnel with a small opening at the top and a handle to hold it. It is used in order to lead the sound of voice in the direction that the speaker aims so as to be heard far away. For it to be lightweight, it is made of light metal or wood in a conical shape. In the era of sailing ships, it was used to enable the communication of ships that sailed at a short distance from each other, or so that the captain’s commands would be heard by the crew when handling the sails, especially when the weather conditions were bad.

The principle of operating the loud hailer is simple. The speaker applies his/her mouth to the small hole at the top of the funnel and speaks loudly. The sound of his/her voice is reflected in the inner walls of the funnel and driven in a narrow beam in the direction the speaker aims. Thus, the volume of the voice in the direction of the funnel is significantly enhanced.

Ever since the medieval times, the loud hailer has been known to sailors as tromba-marina (eng: speaking trumpet, loud hailer; gre: televoas; tur: boru) as metaphor from the Italian language. There was even a single-stringed musical instrument, which was played with a bow and had the same name due to its similar conical shape.

After the discovery of the microphones and the megaphones (loud speakers), contemporary loud hailers operate on batteries, but the principle of operation remains the same.

The loud hailer doesn’t amplify the sound; it just transfers the sound to a more specific area, made of light metal or wood in conical shape (funnel), which was used in the communication of the ships with each other or in giving orders-instructions to the crew as the sound beam headed towards one direction.

In ancient times large seashells were used for the production of sound or sound waves; in the era of Alexander the Great the sound funnel appears; a column 3-4 meters high, which had a funnel on its top part; reportedly, its sound could reach up to 2 km.

During the 17th century the first sound cones appear as an aid for the hard of hearing.

To seafarers it was also known as tromba-marina from the English word (sea) trumpet since the first loud hailers were called speaking trumpets.