Reading a sound waveform
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. In a waveform, what does the left-to-right direction show?
2. In a waveform, what does the up and down height show?
3. Which waveform shows a louder sound?
4. What does a flat line in a waveform mean?
5. A friend shouts, then whispers. What happens to the waveform?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1[0, 0, 0, 0, 0] | AA flat line on the waveform, which means silence | |
| 2[9, -9, 9, -9] | Bx-axis = time | |
| 3Time runs from left to right along a waveform | Cheight = volume | |
| 4The taller the wave, the louder the sound | DSilence is a flat line, not tall waves. Tall waves mean a loud sound. | |
| 5y-axis = time | ETime is on the horizontal x-axis, running left to right. The vertical y-axis shows volume. | |
| 6silence = tall waves | FTall waves, which means a loud sound |
C
Definitions
waveform
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
xAxis = ____
yAxis = volume
2.
IF sound is louder THEN wave is ______
3.
IF volume = _ THEN wave is a flat line
4.
heights = [2, 8, 5, 1]
loudest = ___(heights)
5.
timeDirection = left TO _____
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
x_axis ← time
B
y_axis ← volume
C
loud ← tall wave
D
silence ← tall wave
Question 2
A
FOR each sample in recording
B
height ← time of sample
C
DRAW bar of that height
Question 3
A
FOR each sample in recording
B
IF sample is zero THEN
C
DISPLAY 'tall wave'
D
END IF
Question 4
A
x_axis ← time
B
y_axis ← volume
C
start ← left of graph
D
end ← top of graph
Question 5
A
x_axis ← volume
B
y_axis ← volume
C
peak ← highest point
Answer Key
Reading a sound waveform
Section A: Quick Questions
Q1
B — Time passing
Q2
B — Volume of the sound
Q3
A — Tall waves
Q4
A — Silence
Q5
A — Tall waves, then short waves
Section B: Match the Pairs
Q1
[0, 0, 0, 0, 0] → A flat line on the waveform, which means silence
Q2
[9, -9, 9, -9] → Tall waves, which means a loud sound
Q3
Time runs from left to right along a waveform → x-axis = time
Q4
The taller the wave, the louder the sound → height = volume
Q5
y-axis = time → Time is on the horizontal x-axis, running left to right. The vertical y-axis shows volume.
Q6
silence = tall waves → Silence is a flat line, not tall waves. Tall waves mean a loud sound.
Section C: Definitions
Q1
waveform — A graph of a sound. Time runs left to right and volume goes up and down. Louder sounds make taller waves and silence is a flat line.Section D: Fill in the Blanks
Q1
xAxis = time
yAxis = volumeQ2
IF sound is louder THEN wave is tallerQ3
IF volume = 0 THEN wave is a flat lineQ4
heights = [2, 8, 5, 1]
loudest = MAX(heights)Q5
timeDirection = left TO rightSection E: Spot the Error
Q1
D — Silence has no volume, so its waveform is a flat line, not a tall wave. It should be: silence ← flat line
Q2
B — The height of the wave shows volume, not time. Time runs left to right. It should be: height ← ABS(sample)
Q3
B — A zero sample is silence, which is flat, so it cannot give a tall wave. The test should be: IF sample is large THEN
Q4
D — Time runs from left to right, so the end of the sound is at the right of the graph. The top shows loud volume. It should be: end ← right of graph
Q5
A — On a waveform, time runs along the horizontal x-axis. Volume goes on the vertical y-axis. It should be: x_axis ← time