Question 1

A sound wave is __________________________&#10;A) a variation in air pressure at a point in the range 20 Hz to 20 kHz.&#10;B) an audio signal&#10;C) an electromagnetic wave in the air&#10;D) a vibration of atoms

Accepted Answer

A sound wave is a variation in air pressure at a point in the range of 20 Hz to 20 kHz. It propagates as a pressure wave through a medium such as air, water or solids. Although it can be converted into an audio signal, it is not the same thing as an audio signal, as the latter is an electrical signal that carries information from an audio source. It is also not an electromagnetic wave, which is a type of wave that does not require a medium to propagate.

Question 2

Sound pressure drops _____ dB each time the distance from the source doubles.&#10;A) 3&#10;B) 10&#10;C) 6&#10;D) 1

Accepted Answer

Sound pressure level drops by approximately 6 dB each time the distance from the source doubles, due to the spreading of the sound wave over a larger area.

Question 3

Loud sounds have ____________________.&#10;A) high frequencies&#10;B) low frequencies&#10;C) low amplitude&#10;D) high amplitude

Accepted Answer

Loud sounds have high amplitude, meaning they have a greater energy output and cause larger vibrations in the air, which our ears and brain interpret as a louder sound.

Question 4

One thousand cycles per second is abbreviated __________.&#10;A) 1 kHz&#10;B) 1000 cy/sec&#10;C) 1 kilocycles/sec&#10;D) 1000 waves/sec

Accepted Answer

kHz stands for kilohertz, which represents one thousand cycles per second. The other options are also correct in terms of representing the frequency, but they are not commonly used abbreviations.

Question 5

A high-pitched sound has a ___________________.&#10;A) high amplitude&#10;B) irregular waveform&#10;C) high frequency&#10;D) wide waveform

Accepted Answer

A high-pitched sound is characterized by a high frequency, which means that the sound wave oscillates at a high rate per second.

Question 6

If you combine two identical waves 180 degrees out of phase, what happens?&#10;A) nothing&#10;B) silence&#10;C) constructive interference&#10;D) beats

Accepted Answer

When two identical waves are combined 180 degrees out of phase, they cancel each other out completely, resulting in silence. This is known as destructive interference.

Question 7

A complex wave is made of ______________.&#10;A) fundamental frequencies and harmonics&#10;B) an irregular waveform&#10;C) an out-of-phase waveform&#10;D) several recordings mixed together

Accepted Answer

A complex wave is made up of a combination of fundamental frequencies and their harmonics.

Question 8

Noise (in audio) is ___________________.&#10;A) Undesired sound&#10;B) an irregular waveform&#10;C) often a hiss sound&#10;D) something that can be expressed in S/N&#10;E) all of the above

Accepted Answer

Noise in audio refers to any undesired sound that interferes with or alters the intended signal. It can be an irregular waveform, often resulting in a hiss sound, and is commonly expressed as a signal-to-noise ratio (S/N). Therefore, all of the statements are true and the best choice is E.

Question 9

The four parts of an envelope are _________________.&#10;A) First part, second part, third part, fourth part&#10;B) attack, decay, sustain, release&#10;C) outer edge, inner edge, top limit, bottom limit&#10;D) timbre, maximum, minimum, note shape

Accepted Answer

The four parts of an envelope in music and sound design are attack, decay, sustain, and release. These terms describe the shape of the sound from the beginning to the end, including how it starts (attack), fades (decay), sustains, and ends (release).

Question 10

Sounds with short envelopes ___________________.&#10;A) have quick attacks.&#10;B) are transients.&#10;C) might be a guitar pluck or drum hit.&#10;D) are shorter than sounds with long envelopes.&#10;E) all of the above.

Accepted Answer

All of the options listed are true for sounds with short envelopes. They have quick attacks, are transients, and are shorter in duration compared to sounds with long envelopes. Examples of sounds with short envelopes include guitar plucks and drum hits.

Question 11

The speed of sound is ____________________.&#10;A) about 1 foot per millisecond.&#10;B) 1800 feet per second.&#10;C) 1130 miles an hour.&#10;D) instantaneous.

Accepted Answer

The answer of The speed of sound is ____________________.&#10;A) about...

Question 12

An echo is ____________________.&#10;A) a delay.&#10;B) a repetition of a sound more than 50 milliseconds after the original sound.&#10;C) a smooth decay of sound.&#10;D) something you hear in the mountains.

Accepted Answer

The answer of An echo is ____________________.&#10;A) a delay.&#10;B) a...

Question 13

Reverberation is _____________________.&#10;A) a wiggly, pulsing sound&#10;B) a series of echoes.&#10;C) a delay.&#10;D) acoustic absorption.

Accepted Answer

The answer of Reverberation is _____________________.&#10;A) a wiggly, pulsing sound&#10;B)...

Deck 2: Sound and Psychoacoustics