Golconda, Gol Gumbaz: Marvels of acoustics and architecture

Hyderabad: Can anyone believe that in ancient India about 500 years ago Muslim rulers of Golconda had an advance sound alarm system to alert the security guards in 3 Sq. km when there was no modern communication system?

Golconda was considered to be an impregnable fort during its heyday due to its unbreakable acoustic security system. No one after this fort was built by Mohammed Quli Qutub Shah had ever conquered this fort through force.

Aurangzeb, the Mughal emperor made two attempts to conquer it and both these times he met with failure. Even during his third attempt, he was not able to breach the fort’s security system based on acoustic science.

This impregnable fort’s fall finally occurred due to the betrayal of the Security Incharge. As a result, after two failed attempts, Aurangzeb was able to capture the Golconda fort in 1687.

Ibrahim Quli Qutb Shah, the King who built the Golkonda Fort was believed to be the expert of physics. The evidence of his brilliance was quite evident to the visitor from the very first sight of the fort due to its acoustic effects which are astounding.

It’s amazing to hear the sound of a clap reaching the 400 feet high Citadel from the entrance. Even more amazing was the use of this acoustic effect, combining it with different signals for different happenings. In case of enemy attack, the guards of the citadel would be forewarned.

The architects of this 11 km Sprawling fort – a fortified City – were aware of the sound echo technology, its amplification and the use of earthen pottery for creating the perfect acoustic sound alarm security system.

From the entrance when the visitor sees the fort further, he will be amazed to see how intelligently the fort was planned to put everything in order so that the sound could travel easily. The hall where the public assemblies were held and the hall where relatives and sometimes the soldiers stayed were designed in such a way that even the whisper made by them could be heard by the King in his chamber.

As for the technique used, It is believed that the diamond shaped crests on the roof and the arches leading to the outer court get narrowed gradually to make the sound compressed first and then amplified to travel through them upto 1 km. The careful distance between the doors and the building and the intelligent wall structure also play an important role in this acoustic system. In this system the sound travels back and forth from one end to the other end without losing its intensity.

The ultra security system of the fort was due to two reasons: One: To make the fort impregnable to the attacking armies. Two: Because Golconda was situated on a famous trade route and was an important centre for diamond trade. The Fort was housing diamonds excavated from the famous Kollur mine nearby. It is said that the 13 most precious diamonds of the world including the Kohinoor, Daria-e-Noor, Hope Diamond, and others were believed to be stored in Golconda fort. Thus, there was the need for this ultra security.


This gigantic tomb of India – a single chamber – built by Mohammed Adil Shah in 1656 is another majestic acoustic marvel of India.The whispering gallery here echoes many times any minute sound made here.

This gigantic monument is the second largest tomb in the world and its massive central dome is not supported by any pillar. The dome had been set on pendentive intersecting arches that enabled a circular dome to be placed over a square base.

The Whispering gallery is made above seven storeys. The sound is so engineered in this acoustic marvel of India that anyone standing in the gallery can hear even the minutest sound made by the person standing on the other end 124 feet away. This includes the sound of even a ruffle of paper or the sound of a deep breath.

As was the custom during those days Sultan Adil Shah constructed this grandeur edifice to be his resting place after his death. The mausoleum has the graves of Sultan Adil Shah, his beloved Rambha, two of his wives, and his grandson.

The King during his lifetime used this monument for his secret meetings with his beloved, Rambha. The acoustic effects narrowed the distance between them and when she spoke from the other end he could feel her every word along with the movement she made.

One more interesting feature of this architectural wonder is that when he had the conversation with Rambha on the seventh floor nobody standing below could hear them while they both could hear what was going on the lower levels.

Apart from this, Sultan Adil Shah also held conferences of ministers of other states and secretly heard their conversations.