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What is a complex sound wave?

A sound wave made up of two or more sinusoidal component waves that combine to create a more complicated waveform.

What three properties determine the complexity of a sound wave?

Frequency, Amplitude, and Phase.

What is frequency?

The number of cycles or vibrations occurring per second, measured in Hertz (Hz).

What is amplitude?

The magnitude or height of a sound wave, relating to the strength of the sound.

What is phase?

The relative starting position of a wave within its cycle.

What does periodicity refer to?

Whether a sound wave repeats its pattern over time.

What are the three classifications of sound waves?

Periodic, Quasiperiodic, and Aperiodic.

What is a periodic wave?

A wave that repeats itself exactly from cycle to cycle.

What is a quasiperiodic wave?

A wave that is reasonably periodic and repeats approximately from cycle to cycle, but does not repeat exactly.

What is an aperiodic wave?

A wave that does not repeat in a regular pattern and whose frequencies are not harmonically related.

What is a pure tone?

A single sinusoidal sound wave that is always periodic.

What is a complex periodic wave?

A wave that contains multiple sinusoidal components that repeat in a consistent pattern.

What is a complex aperiodic wave?

A wave that contains multiple frequency components that do not have a harmonic relationship.

What are complex aperiodic waves commonly called?

Noise.

What is Fourier analysis?

The mathematical process of breaking down a complex sound wave into its individual sinusoidal component waves.

What is the fundamental frequency?

The sinusoidal component with the lowest frequency in a complex periodic wave.

What is special about the fundamental frequency?

It is the first harmonic and generally contains the greatest amount of power or energy among the components.

What are harmonics?

Frequencies that are whole-number multiples of the fundamental frequency.

What is the first harmonic?

The fundamental frequency itself.

What is the second harmonic?

Twice the fundamental frequency.

What is the third harmonic?

Three times the fundamental frequency.

What are overtones?

Frequencies above the fundamental frequency; the first overtone is the second harmonic.

What is a harmonic relationship?

Exists when the frequencies of the sinusoidal components are whole-number multiples of the fundamental frequency.

What is an odd-and-even harmonic relationship?

Contains both odd-numbered and even-numbered multiples of the fundamental frequency.

What is an even-only harmonic relationship?

Contains only even-numbered multiples of the fundamental frequency.

What is an odd-only harmonic relationship?

Contains only odd-numbered multiples of the fundamental frequency.

What happens to acoustic energy in a complex periodic wave?

Acoustic energy exists only at specific harmonic frequencies, with no energy between those frequencies.

What is an amplitude spectrum?

Represents amplitude as a function of frequency.

What does the horizontal or x-axis of an amplitude spectrum represent?

Frequency, measured in Hertz.

What does the vertical or y-axis of an amplitude spectrum represent?

The relative amplitude or strength of each frequency component.

What does each vertical line in an amplitude spectrum represent?

An individual frequency component or harmonic.

What determines the location of a vertical line in an amplitude spectrum?

The frequency of the component wave.

What determines the height of a vertical line in an amplitude spectrum?

The relative amplitude of that frequency component.

What does 0 dB represent on the amplitude spectrum?

The amplitude of the component with the greatest energy, used as the reference for the other components.

What is the general harmonic amplitude decline?

Harmonics generally decrease by approximately 6 dB per octave.

What is an octave?

A doubling of frequency; for example, 500 Hz to 1,000 Hz is one octave.

What does a decrease of 6 dB per octave mean?

When frequency doubles, the amplitude level decreases by 6 dB.

What does an amplitude spectrum tell us?

It shows which frequencies are present in a sound and the relative amount of energy or amplitude associated with each frequency.

What is wave summation?

Occurs when two or more sound waves combine to produce a resulting waveform.

What factors influence wave summation?

Frequency, Amplitude, Phase, and Number of component waves.

What is a square wave?

A complex periodic waveform containing only odd-numbered harmonics, decreasing by approximately 6 dB per octave.

What is a sawtooth wave?

A complex periodic waveform containing both odd- and even-numbered harmonics, decreasing by approximately 6 dB per octave.

What is a triangle wave?

A complex periodic waveform containing only odd-numbered harmonics, decreasing by approximately 12 dB per octave.

How are square waves and sawtooth waves similar?

Both decrease at approximately 6 dB per octave.

How are square waves and sawtooth waves different?

Square waves contain only odd harmonics, while sawtooth waves contain both odd and even harmonics.

How are square waves and triangle waves similar?

Both contain only odd-numbered multiples of the fundamental frequency.

How are square waves and triangle waves different?

Square waves decrease by 6 dB per octave, while triangle waves decrease by 12 dB per octave.

How are sawtooth waves and triangle waves different?

Sawtooth waves contain odd and even harmonics and decrease by 6 dB per octave, while triangle waves contain only odd harmonics and decrease by 12 dB per octave.

What is the main difference between complex periodic and complex aperiodic waves?

Complex periodic waves repeat exactly from cycle to cycle and contain harmonically related frequencies.

What are complex periodic waves?

Waves that repeat exactly from cycle to cycle and contain harmonically related frequencies.

What are complex aperiodic waves?

Waves that do not repeat regularly and do not contain harmonically related frequencies.

What is noise?

Noise is a complex aperiodic sound.

Give examples of complex aperiodic sounds.

/s/, /sh/, a hard clap, a door slam.

What is white or Gaussian noise?

White noise contains equal energy or amplitude across all frequencies within its frequency range.

What is a continuous amplitude spectrum?

A spectrum that displays energy across all frequencies within certain limits rather than individual vertical lines at isolated frequencies.

What is a transient?

An abrupt sound of such short duration that it does not have the opportunity to repeat itself, like a hand clap or door slam.

How does an aperiodic amplitude spectrum differ from a periodic amplitude spectrum?

A periodic wave has individual vertical lines representing specific harmonic frequencies, while an aperiodic wave has a continuous spectrum of frequencies.

What is sound propagation?

The movement of sound energy away from its source through a medium.

What is spherical propagation?

Propagation that occurs when sound waves travel outward from their source simultaneously in all directions, forming an expanding spherical pattern.

What is the inverse square law?

It describes how sound intensity decreases as distance from the source increases.

What is the relationship between sound amplitude and distance?

Sound amplitude decreases as the distance traveled increases.

What is damping?

The reduction or attenuation of vibration amplitude over time due to energy loss.

What is the difference between damping and the inverse square law?

Damping describes the decrease in amplitude over time, while the inverse square law describes the decrease in sound intensity as distance from the source increases.

What is sound absorption?

The process when sound energy enters a material or structure and is converted into another form of energy, primarily heat.

What is sound reflection?

The occurrence when sound waves bounce off a surface or barrier rather than being absorbed.

What is the relationship between sound absorption and reflection?

They are inversely related: as absorption increases, reflection decreases and vice versa.

What are reverberations?

Reflected sound waves that continue to be heard after the original sound has been produced.

What is an echo?

A reflected sound that can be heard as a distinct repetition of the original sound.

What is reverberation time?

The amount of time required for sound pressure level to decrease by 60 dB after the original sound source stops.

What does a long reverberation time cause?

It causes sounds to persist longer, potentially overlapping with subsequent sounds and reducing speech clarity.

What is speech smearing?

The degradation of speech clarity that occurs when outgoing sound waves interact with incoming reflected sound waves.

How does sound absorption impact reverberation time?

Increased sound absorption generally decreases reverberation time because less sound energy is reflected back into the room.

How does sound reflection impact reverberation time?

Increased sound reflection generally increases reverberation time because more sound energy remains in the environment.

What causes damping in a system?

Damping occurs due to internal friction and resistance, causing energy to be lost, often as heat.

What is the impact of air resistance on sound vibration?

Air resistance creates frictional resistance that reduces vibration amplitude and converts some sound energy into thermal energy.

What is the relationship between velocity and damping?

As velocity increases, damping increases; as velocity decreases, damping decreases.

What is a low-damped system?

A system that vibrates for a relatively long time with a gradual decrease in amplitude.

What is a high-damped system?

A system that vibrates for a relatively short time with a rapid decrease in amplitude.

What is a critically damped system?

A system that is so highly damped that it stops vibrating almost immediately without continuing to oscillate.

Why does a tuning fork's vibration eventually stop?

Its vibration decreases because energy is lost through internal friction and through transferring energy to the surrounding air, a process called damping.

What happens when sound energy encounters a barrier and is absorbed?

The sound energy enters the barrier and is converted into thermal energy or heat.

What is the glottal tone?

The sound produced by vibration of the vocal folds, containing a fundamental frequency and harmonics.

What are the limitations of the glottal tone?

It does not contain all the acoustic characteristics necessary to produce recognizable speech sounds, particularly distinctive vowels.

What is the role of the supralaryngeal system?

It modifies the sound produced by the vocal folds through resonance and filtering, helping create recognizable speech sounds.

What is the supralaryngeal cavity?

The area above the level of the vocal folds, including the pharynx, oral cavity, and nasal cavity.

What is the difference between the laryngeal and supralaryngeal systems?

The laryngeal system produces the original glottal sound, while the supralaryngeal system modifies that sound through resonance and articulation.

Why is the supralaryngeal system important for speech?

It allows the production of different vowels and consonants by changing the shape and configuration of the vocal tract.

What is resonance?

The frequency-selective reinforcement of sound energy that occurs when an external vibration approaches a system's natural or resonant frequency.

What is a resonator?

An object or structure that vibrates in response to sound energy and reinforces certain frequencies.

What is the difference between a sound source and a resonator?

A sound source initiates or creates sound energy, while a resonator reinforces specific frequencies produced by another source.

Does a resonator create sound energy?

No, a resonator does not create or initiate sound energy; it reinforces frequencies consistent with its physical characteristics.

What is a natural or resonant frequency?

The frequency at which a system naturally vibrates when disturbed.

What is free vibration?

Free vibration occurs when a single application of an external force causes an object to vibrate at its natural or resonant frequency.

What is forced vibration?

Forced vibration occurs when an object vibrates at a rate determined by the frequency of an external source of vibration.

What happens when a tuning fork is struck?

Striking a tuning fork causes it to vibrate freely at its natural frequency.

What happens to a tuning fork's amplitude over time?

Its amplitude gradually decreases because of damping and energy loss.

What happens when a vibrating tuning fork is placed against a hard surface?

The hard surface is forced to vibrate along with the tuning fork, reinforcing the sound energy and making the sound louder.

What is reinforcement of sound energy?

Reinforcement occurs when a resonator responds to an external sound source and increases the amplitude of vibration at or near its resonant frequency.

How does resonance affect loudness?

Resonance increases the amplitude of vibration, which increases sound pressure and makes the sound louder.

What is power in relation to sound?

Power is the rate at which energy is transferred or used over time.