Building Acoustics and Lighting Design for Office, Speech, Music, and Movie Theaters

What is the primary purpose of sound absorbing materials in auditoriums?

To control echoes and reverberation.

Why is excessive reverberation problematic for listeners?

It can seriously interfere with listening conditions, especially for the hearing impaired and older persons.

Where should sound absorbing materials not be used?

On surfaces that could provide useful sound reflections.

What is a recommended method for controlling noise build-up in rooms?

Use sound absorbing ceilings unless the floor is carpeted and the room has heavy draperies.

What design feature helps bring a large audience closer to the stage in auditoriums?

A floor plan with diverging side walls.

What are typical characteristics of acoustical design for office buildings?

Multistory structures with air handling units on each floor and mechanical equipment on the roof.

What complicates room-to-room noise transmission in high-rise office towers?

High air velocities and common plenum air return systems.

What type of barriers can control direct sound paths in office environments?

Full height barriers and absorptive materials like fiberglass panels.

What is essential for adequate loudness in rooms designed for speech?

A high direct field level and controlled distance between the source and receiver.

What are the fundamental requirements for rooms designed for speech?

Adequate loudness, uniform sound levels, appropriate reverberation, low background noise, and absence of acoustical defects.

What is a recommended ceiling type for lecture halls and auditoriums?

A hard ceiling is preferred.

What is a key design parameter for rooms intended for music?

The audience should feel enveloped by sound with evenly distributed loudness.

What materials are commonly used for walls and ceilings in concert halls?

Heavy plaster and concrete.

What is the typical seating capacity range for successful concert halls?

1,700 to 2,600 seats, with an average around 1,850.

What is the primary function of an opera house in terms of design?

To balance the level between the singer and the orchestra, with the orchestra seated in a pit.

What are the general acoustic considerations for movie theaters?

Speech intelligibility, high sound absorption materials, and avoidance of reflective surfaces.

What type of fabric is recommended for seats and curtains in movie theaters?

Heavy fabrics to enhance sound absorption.

What should be done to the floors in movie theaters to improve acoustics?

Cover them with carpet to avoid reflective surfaces.

What is the role of curved rear walls in concert halls?

To help diffuse reflected sound energy.