2. Sound and perception

Question 1

What is the medium for sound propagation in speech?

Answer 1

Air

Sound requires a medium to travel, and air is the primary medium for speech.

Question 2

What physical property of sound refers to how often a wave repeats per second?

Answer 2

Frequency

Frequency is a crucial concept in understanding sound waves.

Question 3

Frequency is measured in which unit?

Answer 3

Hertz

Hertz (Hz) is the standard unit for frequency, indicating cycles per second.

Question 4

What is wavelength?

Answer 4

It is the distance between two successive cycles of a wave

Wavelength is a key characteristic of waves and relates to frequency.

Question 5

What is the inverse relationship between frequency and wavelength?

Answer 5

Higher frequency = shorter wavelength

This relationship is fundamental in wave physics.

Question 6

The speed of sound in air at room temperature is approximately:

Answer 6

343 m/s

The speed of sound can vary based on temperature and medium.

Question 7

Intensity is proportional to the square of which physical property?

Answer 7

Amplitude

Understanding this relationship is important for sound intensity calculations.

Question 8

Which unit is used to measure sound intensity level?

Answer 8

Decibels (dB)

Decibels are used to quantify sound levels in a logarithmic scale.

Question 9

What physical dimension of sound does the perceptual term ‘pitch’ correspond to?

Answer 9

Frequency

Pitch perception is closely linked to the frequency of sound waves.

Question 10

What is the perceptual correlate of amplitude?

Answer 10

Loudness

Loudness is how we perceive the intensity of sound.

Question 11

What is the approximate range of human hearing in Hz?

Answer 11

20–20,000 Hz

This range varies among individuals and can be affected by age.

Question 12

What are the characteristics of simple harmonic motion?

Answer 12

It is periodic and sinusoidal

Simple harmonic motion is a fundamental concept in wave mechanics.

Question 13

Complex periodic waves are composed of:

Answer 13

A fundamental frequency and its harmonics

Complex waves are essential in understanding musical tones.

Question 14

The lowest frequency in a complex periodic sound is called:

Answer 14

Fundamental frequency

The fundamental frequency determines the pitch of the sound.

Question 15

The human voice typically produces which type of sound wave?

Answer 15

Complex periodic wave

This type of wave allows for the rich texture of human vocalization.

Question 16

An aperiodic waveform is characterized by:

Answer 16

No predictable pattern

Aperiodic waveforms are common in noise and non-repetitive sounds.

Question 17

Which tool transforms a waveform from the time domain to the frequency domain?

Answer 17

Fourier Transform

The Fourier Transform is essential in signal processing.

Question 18

In a spectrum, what does each vertical line represent in a complex periodic sound?

Answer 18

Frequency component

Each line correlates to a specific frequency present in the sound.

Question 19

What type of graph shows how energy is distributed across frequency in a sound?

Answer 19

Spectrum

Spectrums provide insights into the frequency content of sounds.

Question 20

Which representation of sound shows changes in frequency and amplitude over time?

Answer 20

Spectrogram

Spectrograms are valuable for analyzing dynamic sounds.

Question 21

In a spectrogram, darker areas typically indicate:

Answer 21

Greater amplitude

This visual representation helps in understanding sound intensity.

Question 22

What does the vertical axis represent in a waveform?

Answer 22

Amplitude

Amplitude in a waveform indicates the strength of the signal.

Question 23

What is the horizontal axis in a spectrogram?

Answer 23

Time

Time is critical for observing how sound evolves.