Volume Fundamentals

Question 1

What is an envelope?

Answer 1

Evolution of the amplitude of the sound, represented as an idealized line that links the positive peaks of its waveform

Question 2

What are the four basic stages of an envelope?

Answer 2

Attack - during when the amplitude(volume) rises from zero to maximum amplitude

Decay - where the amplitude(volume) decreases to a certain level

Sustain - where the amplitude(volume) remains constant

Release - where the amplitude(volume) recedes to zero

Question 3

What are transients?

Answer 3

Sudden change a voltage (most often heard as volume, usually think of it with more percussive instruments).

Question 4

What are three basic guidelines to remember when dealing with logarithms?

Answer 4

1. The log of 2 is 0.3
2. When a number is an integral power of ten(100, 1,000, 100,000), the log number can be found by simply adding up the zeros.
3. Numbers greater than 1 will have positive log values, numbers less than 1 will have negative log values.

Question 5

Volume for sound can be measured in these, three ways:

Answer 5

1. SPL
2. Voltage
3. Power

Question 6

What is dB SPL?

Answer 6

Acoustic pressure that’s been built up within a defined atmospheric area (usually cm2)

Question 7

What is the threshold of hearing?

Answer 7

Threshold of Hearing = softest sound audible to the human ear.

Most conversations are around 70 dB
Stereos at home play at around 80-90 dB SPL

Question 8

What is the threshold of feeling?

Answer 8

Threshold of Feeling = An SPL that causes discomfort 50% of the time = 118 dB SPL between frequencies 200Hz-10,000Hz

Question 9

What is the threshold of pain?

Answer 9

Threshold of Pain = sounds that are so loud that they cause us pain
Usually around 130-140 dB (10,000,000,000,000 x louder than 0 dB)

Question 10

What is dBv?

Answer 10

Decibels per voltage:

Refers to the pressure behind the electrons in the wire

Question 11

What is dBp?

Answer 11

dB Power = is the measure of wattage or current (flow of electrons).

Question 12

How would you describe acoustic loss?

Answer 12

Acoustic Loss - when the ear is exposed to sudden loud noise in excess of 140 dB SPL, Causes permanent hearing loss

Question 13

What is temporary threshold shift?

Answer 13

Temporary Threshold Shift - The can be exposed to hearing loss through long term , loud noise

Question 14

What is permanent threshold shift?

Answer 14

Permanent Threshold Shift - Extended exposure to loud noises. Permanently damaging a specific frequency range of hearing.

Question 15

What are some ways to take care of your hearing?

Answer 15

Avoid hazardous sound environments, wear earplugs

Monitor sound pressure levels at 85 dB and higher, if you have to raise your voice to be heard, then you are monitoring too loudly

Take 15 minute quiet breaks, every few hours if you are being exposed to levels above 85 dB

Musicians should avoid practicing at concert hall levels

Have your ears checked periodically by a licensed audiologist

Question 16

What are psychoacoustics?

Answer 16

The study of how and why the brain interprets a particular sound stimulus in a certain way

Question 17

What is the acoustic phenomena known as beating?

Answer 17

Tones that vary in frequency and have approximately the same amplitude will produce an effect known as beating

This effect sounds like repetitive surges in volume

Closer the frequencies are the slower the beating effect

Faster the frequencies are, the faster the effect

The effect can be measured in seconds by the cycles per second

Question 18

What is the acoustic phenomena known as combination tones?

Answer 18

the ear produces an additional set of tones that are the sum and difference of the original tones

2000, 2500

There will be perceive the difference of these tones

500

And the summation of these tones

4500

Question 19

What is the acoustic phenomena known as audio masking?

Answer 19

Masking = the phenomena by which loud signals prevent the ear from hearing softer sounds. The effect is more pronounced when the frequencies are close to one another.