ECS- Chap 6 & 7 Study Guide

A diffuse surface will exhibit uniform brightness if the spacing between light sources does not exceed approximately _______ times their distance from the material

1.5

The critical frequency range for human speech communication is:

300 to 4000 Hz

The Articulation Index (AI) is determined by reading a carefully selected set of phonetically balanced nonsense syllables to a test audience in the presence of different levels of background noise. An AI (ratio of correctly identified syllables to total syllables) of ______ is usually deemed an acceptable level of intelligibility for a male voice.

0.5

What illuminance is most suitable for the general book stacks in a high school library?

100 lux

A typical sound pressure level (dBA) for human breathing is 10, and for a jet plane takeoff is 150. The threshold of discomfort is about ____ dBA.

110

Human beings can hear sounds with frequencies ranging from:

20 to 20,000 Hz

Sound intensity level changes by 3 dB with every doubling or halving of power and changes by _______ dB with every doubling or halving of the distance from a point source

6

Which of the following terms does NOT relate to sound magnitude

sound frequency

The relationship between brightness and luminance can best be described in the following way:

Both are terms used to describe light coming off of an object, however brightness is subjective and luminance is measurable.

The SI unit of luminous intensity is the:

Candela

Illuminance is measured more frequently than luminance because:

Design recommendations for lighting levels are typically given in terms of illuminance

The relationship between illuminance and luminance for an opaque surface is best described as:

Luminance is illuminance as modified by reflectance

Prolonged exposure to high noise levels can lead to hearing loss. Which of the following US-based agencies publishes acceptable noise exposure limits for workers?

OSHA

The reflection that occurs with a smooth surface such as polished glass or a mirror is called:

Specular Reflection

Photometric readings are usually taken at the height of a "working plane" because:

This approximates the height of typical visual tasks

When a light source produces energy over the entire visible spectrum in approximately equal quantities, the light appears as

White

The decibel is best defined as the following:

a numerical scale devised to conveniently describe sound magnitude

"Veiling reflections" are primarily a problem that occurs with

computer screens and specular surfaces

The goal of architectural acoustics is as follows:

design spaces to meet hearing needs

Illuminance levels and illuminance categories are used to:

establish quantitative lighting system design criteria

Which of the following is NOT a correct conclusion regarding annoyance as a result of noise? Annoyance is:

greater for nonsense ration (foreign language) than information-bearing noise (a neighbor's radio)

In architectural acoustics, frequency is sometimes referred to as:

pitch

The following is NOT a definition of noise:

sound outside of the normative frequency ranges

Illuminance is best defined as:

the density of luminous energy expressed as lumens per unit area