Acoustics and Sonic Research

This section summarizes my acoustic research projects at the Rensselear Polytechnique Institute (RPI) to fulfill the Master's degree at the Architectural Acoustics program. A significant part of my research is dedicated to my thesis project under Professor Jonas Braasch's supervision. Some other presented materials are outcomes of the Sonic Research Lab projects under Professor Xing Niang's supervision. Besides my interest in architectural space's impact on 

shaping our sonic landscape, I am fascinated by the audio technology aspect of acoustic science and sound simulation techniques. My thesis project contains a section in architectural acoustics study and s section dedicated to sound simulation. The experimentation and testing are done at RPI's CRAIVE lab, which is equipped with a 128 speaker array for Wave Field Synthesis and a 360 panoramic screen. I am also using my architectural design and modeling skills to create an immersive experience as an outcome of this project. 

Research Interests: 

  • Architectural Acoustics

  • Wave Field Synthesis

  • Ambisonic System

  • Binaural Auralization

  • Extended Sound Sources Simulation

  • Immersive Experience 

Abstract

   Spatial audio rendering techniques have created the opportunity for advancement in audio simulation and the study of auditory scene analysis. Pipe organs with their immense size, inherit their sound envelopment properties from the spatial characteristics of the architectural space that encompasses them. In other words, the instrument and space create an audio apparatus unique in its kind. This paper focuses on studying the spatial characteristic of pipe organ sound and the

sonic landscape created within a virtually modeled architectural space based on ray tracing. The design of the space is the result of a thorough study of an Iranian architecture element called “Muqarnas.” Muqarnas is a stalactite vaulting system based on the replication of uniformly scaled modules arranged in tiers. Its shape creates a smooth transition from walls to ceilings and a dome-shaped enclosure. The virtually designed space will be sculpted around the organ ranks in

such a way that together they create a spatially inhabitable musical instrument. Using wave field synthesis and panoramic visual rendering in RPI’s CRAIVE Lab, the goal is to create an immersive audio-visual experience. The system is also used to study the human perception of extended sound sources in reverberant environments. My Current research topic is Simulation Of Extended Sound Sources (Pipe Organ) using Wave Field Synthesis.

Acoustics in​ Islamic Architecture

  Architectural acoustics in historic Islamic architecture is a relatively untouched domain for researchers and acousticians. However, a wide variety of architectural spaces with unique forms and geometries, especially in public buildings such as mosques, schools, public baths, can offer ample opportunities for curious architectural acousticians. For instance, in a typical mosque, spaces like prayer hall, courtyard, mihrab, portal, or features like minarets and domes all

Muqarnas​ (the understudy element)

contribute to the sonic landscape of these architectural entities. Furthermore, one should not neglect the role of ornamentation, which adds another layer of complexity and aesthetic values to the formation of these spaces. 

mohammad-domiri-documents-the-intricacy-

Jameh Mosque of Yazd in Yazd, Iran

Photo by Mohammad Reza Domiri Ganji 

Source: Designboom 

   In this research, one of the most articulated archetypal forms of Islamic Architecture called Muqarnas - that has both structural functionality and ornamental beauty - is the subject of investigation. Muqarnas is a decorative vaulting system that creates a smooth transition from a room's walls into a domed ceiling.[1] This element originated in Egyptian Islamic architecture and later was articulated by Iranians during the Safavid era, and is one of the most

Music and Religious Spaces 

significant motifs of their architecture. The application of Muqarnas is not limited to the interior space of a building. Moreover, it contributes to the urban landscape in entrance portals (Iwan) of mosques, public buildings, and bazaars' arches. The unique geometrical properties of this element, which have a modular and rotational nature, along with the proportional and volumetric specification of the space it encompasses, is the acoustical subject of study in this research. 

mohammad-domiri-iran-photography-designb

Timche-ye Amin Od-dowleh, Kashan, Iran

Photo by Mohammad Reza Domiri Ganji 

Source: Designboom 

   Despite the shortage of literature in the acoustical study of Islamic Architecture, researchers have done a considerable amount of work in the analysis and modeling of equivalent building types in the western world. In contrary to the Islamic world, the utilization of music in the practice of Christianity has made churches an engaging topic for acousticians. During the years, 800 and 900 pipe organs started to find their place

Pipe Organ

in religious services and therefore started to become a component of churches and Monasteries. [2]

mohammad-domiri-iran-photography-designb

Ceiling of Alī Qāpū, Isfahan, Iran

Photo by Mohammad Reza Domiri Ganji 

Source: Designboom 

Pipe organs with their immense size are bound to the architectural space that inhabits them, and the sound of the instrument reflects the space's acoustical properties, which makes the architectural space analogous to the body of the instrument. Also, due to their pipes' distribution pattern, pipe organs can be the subject of study as an extended sound source. As a result, this instrument has been borrowed by the author as a tool for 

Methodology 

acoustical analysis of the targeted architectural space under study. The known impact of church acoustics [3] on the sound of this instrument is a building block for comparison and evaluation of the sonic landscape created in Islamic Architecture and, more specifically, the subject of interest in this research Muqarnas. 

st-patricks-cathedral-pipe-organ-james-a

St. Patrick's Cathedral - Pipe Organ

Photo by James Aiken 

Source: Fin Art America 

  The methodology pursued in this project's acoustical analysis is based on some known techniques in architectural acoustics such as the ray-tracing method and measurement algorithms introduced by simulation software like CATT acoustics. However, to optimize the computation time and validity of collected data, a decomposition method is proposed in which a large-scale acoustics problem is broken down into smaller

problems with different scales and measurement accuracy requirements. [ ] For the small scale, Muqarnas itself as an architectural motif is the test's subject. This part of the study reveals the impact of the element's geometrical properties as an acoustical device and its behavior in a specific sound field to reflect, diffuse, or diffract sound. In order to achieve this goal, this element is subtracted from the rest of the space and being analyzed as an individual object in a neutral acoustical environment. On a larger scale, this architectural element will be studied

as the building block of an architectural entity such as a mosque. Based on the small scale analysis, an imaginary architectural space is virtually created and modeled that uses muqarnas acoustical properties as the primary tuner of the sonic environment. Eventually, a pipe organ sound is being simulated within the virtual space as a tool for qualitative measurements and the study of extended sound sources in the realm of psychoacoustic and musical acoustics. 

Screen Shot 2020-06-25 at 1.35.42 PM.png

Ray-tracing Method

catt.png

PLACEHOLDER IMAGE

CATT Acoustics Modeling