Amogh N P
✦ In loving memory of Amogh N P — Architect · Designer · Visionary ✦
B.Arch Curriculum · Semester 5 · Elective

Acoustics in Architecture

Architecture is seen, but it is also heard — and sound, left to chance, ruins a room. This elective makes acoustics a design tool: the physics of sound and the decibel; how sound reflects, absorbs and reverberates, with Sabine's formula to size it; the room defects — echo, flutter, focusing — and their cures; noise control and sound insulation, the difference between absorbing and blocking; and the acoustic design of the auditorium, where the whole art comes together. A field begun, in 1900, by one physicist and one concert hall.

5Units
6Outcomes
4Credits
FreeForever
Start with Unit I All student courses
Unit V · Where it all comes together

Auditorium Design

The auditorium is acoustics' supreme test, where every principle of the course meets. Its design balances volume per seat (which sets the achievable reverberation time), a raked floor for direct sound and sightlines, a shape that distributes sound without focusing, and reflectors that deliver strong early reflections within 50 ms of the direct sound. Different uses want different reverberation times. It is a field born in 1900, when one young physicist, Wallace Sabine, made Boston Symphony Hall the first room ever designed by calculation.

Volume per seatEarly reflectionsRT targetsSabine 1900Hall shapes
Open the lesson

The syllabus

Five units, from the decibel to the concert hall.

Transcribed from the official B.Arch syllabus. All 5 units are live as full interactive lessons, each with original diagrams, a self-assessment quiz and a studio task.

1

Unit 1 — Fundamentals of Sound

Live

The nature of sound — a longitudinal pressure wave; frequency, wavelength and amplitude; the audible range and the speed of sound; the decibel and sound pressure level; the inverse-square law and adding decibels; and human hearing and the dBA.

CO1
2

Unit 2 — Behaviour of Sound

Live

How sound reflects, absorbs, transmits, diffracts and diffuses; the absorption coefficient and the sabin; reverberation and reverberation time; Sabine's formula and the optimum RT for different uses.

CO2CO1
3

Unit 3 — Room Acoustics & Defects

Live

The acoustic defects — echo, flutter echo, sound focusing, dead spots, excessive reverberation, resonance — their causes and cures; and acoustic correction — porous, panel and Helmholtz absorbers, diffusers and room shape.

CO3
4

Unit 4 — Noise Control & Insulation

Live

Airborne and structure-borne noise; sound insulation and transmission loss; the mass law and the STC rating; the NRC; the difference between absorption and insulation; source-path-receiver control; and the CPCB ambient-noise standards.

CO4CO6
5

Unit 5 — Auditorium Design

Live

The acoustic design of the auditorium — volume per seat, floor rake, shape, early reflections and reflectors, sound reinforcement and RT targets; acoustics for other building types; and the story of Sabine and Boston Symphony Hall.

CO5CO6

Course outcomes

What you should be able to do after completing all five units (CO1–CO6, from the syllabus).

1
Understand

Understand the physics of sound and how it is measured (the decibel).

2
Apply

Apply the behaviour of sound and Sabine's formula to reverberation.

3
Analyse

Diagnose room-acoustic defects and prescribe acoustic correction.

4
Apply

Apply noise control and sound insulation in buildings.

5
Create

Apply acoustic principles to the design of an auditorium and other building types.

6
Understand

Understand acoustic standards (CPCB, NBC) and design responsibility.

Topics follow the published B.Arch elective syllabus (L1 · T0 · S5; 200 marks) — the dedicated, deeper companion to the acoustics topic of Building Services. Every diagram is original Studio Matrx work; the formulas (Sabine, mass law) and CPCB figures are verified. We flag the myths — two equal sources add +3 dB not double, absorption is not insulation, and foam does not soundproof.

Architecture is heard, too.

Sound physics, reverberation and Sabine's formula, room defects, noise control and the auditorium. Read the five units, study the diagrams, then test yourself.

Open Unit I Back to Students

Studio Matrx is a tribute to Amogh N P. The curriculum is free, forever.