Lesson 8: Sound Masking

Question 1

Who needs sound masking?

Answer 1

Privacy and noise are big issues in open offices.

Health Care and related fields require their protection of sensitive patient information. (HIPPA)

Question 2

Sound masking works because it raises the ___ floor in an environment.

Answer 2

accoustic.

Question 3

Loudness of a masking system should be set to be ___ to ___ dB higher than ambient level.

Answer 3

3 - 5

The system usually must be adjusted after the client moves in.

Question 4

The signal must cover the frequency range of ___.

Answer 4

human speech of the range. (100 Hz - 6kHz)

Question 5

The sound from a masking system must do two, and only two things.

Answer 5

1. must mask speech

2. must not be a distraction

Question 6

Articulation Index (AI), What is the goal of this masking system?

Answer 6

Test for determining how well a masking system works based on the articulation index. (ASTM test E-1130) Normally used to determine hearing loss in a patient. The goal is to make things harder to hear.

Question 7

What are different factors when selecting the signal source and masking system in an Articulation Index (AI)?

Answer 7

Frequencies of a male and female voice and their loudness
Ambient noise in the space
Accoustical properties of the site’s interior construction and furnishings.

Question 8

What factors of sound calibrating come into play when calibrating the system to deliver comfortable sound?

Answer 8

Plenum heights
Type of ceiling tiles.
Various ceiling penetrations (plenums, air returns, smoke detectors)
Varied ceiling heights
Furniture/work station configurations.

Question 9

What are the most common problems that affect sound quality and comfort in sound systems?

Answer 9

Hot and cold spots
Distracting sound of the system
Loss of sound uniformity

Question 10

Fire alarm and sound masking

Answer 10

NFPA 72 (fire alarm code) requires that the fire alarm system have the ability to turn off the sound masking under certain circumstances.
Usually only required for voice activation systems.

Question 11

Most masking systems have a ___, an ____, an ___, and ____ to carry the sound.

Answer 11

sound source
amplifier
equalizer
speakers

Question 12

Sound masking should or should not be noisy or intrusive in any way.
Sound masking does or does not make work areas seem louder.

Answer 12

should not

does not

Question 13

Sound masking systems are or are not the same as white noise.

Answer 13

are not

Question 14

Masking systems produce a sound that should be ___ and ___ uniform throughout a given space.

Answer 14

non-directional

harmoniously

Question 15

The random, ___ sound from the masking systems generally over-rides the room sound.

Answer 15

ambient

Question 16

Why do most work places need sound masking?

Answer 16

• Many businesses are now allotting less space to employees within open plans, upping the number of people within a room in order to cut overhead. The trend toward a “team” environment has brought upper mgmt and other execs out of their once private office and into the mix.
• As office walls come down and more employees are packed together into the workplace, privacy is affected. Industry research indicates that workplaces will continue to become noisier, affecting employee productivity, morale and retention.