Like in many sites all over the world, until the diffusion of electricity in housing, the sounds of doorknockers were the most important building “voices” of the “Barri Gòtic” of Barcelona during the day. However, the night watchman was the person who opened the doors during the night. Nowadays these sounds remain in few particular buildings using specific codes with loud knock called as “pics i repicons”. These ones are transmitted by the architecture and the environment – which are the soundboard- until they reach the receptors. At this moment, the research stands out because of the methodological discoveries about the state of the Art and the following study. The analysis of the doorknocker sound is very complex. It starts by studying the diversity of people who use it –each one with a particular emphasis. The main study of the sound that origins at the doorknocker takes into account the material and the different parts it is formed by. Moreover, we should pay attention to the esthetic aspect and the symbology that it has. The sound is amplified by different ways: the wood door -that holds the doorknocker-, the street, the hall, the staircase and the courtyards; it arrives to the interior and exterior windows of the house until the receptor gets the information. In order to avoid the disappearance of this historic and cultural sonorous patrimony, we think that it should be classified and geolocated, getting as much information as possible including photos, drawings, plans, recordings and surveys of users –both the speaker and the receiver, among others. In brief, we are working on a trustworthy scientific and artistic study.