Speech Science Test #2

periodic complex sound waves

they repeat themselves exactly from one cycle to the next

Quasiperiodic Complex Sound Waves

appear reasonably periodic b/c almost all features present in one cycle are duplicated in all other cycles, they have some degree of periodicity

aperiodic complex sound waves

characterized by complete lack of periodicity, broken into periods of time, random

fourier analysis

the process by which a complex wave is decomposed or broken down into its component simple sinusoids so that each of those waves can be analyzed individually according to its amplitude, frequency, and phase

Harmonic Relationships

the frequencies of all the simple sinusoids of a complex wave must be integral or whole number multiplieres of the sinusoid with the lowest frequency

fundamental frequency

the lowest frequency

What harmonic relationship does the human vocal tracts produce?

odd only

amplitude spectrum

graphic representation as amplitude as a function of frequency

x-axis

represents frequency

y-axis

the height of each line represents relative amplitude

Amplitude decreases at a rate of ______ per octave

-6 dB

Determines complexity of a sound wave

number of waves, amplitude, frequency, phases of each of those waves

octave

doubling of frequency

square waves

complex periodic wave resulting from the summation of any number of odd multiples of the fundamental frequency decreasing at a rate of -6 dB per octave with each wave having the same starting phase

sawtooth waves

complex periodic wave resulting from the summation of any number of odd+even multiples of the fundamental decreasing at a rate of 6 dB per octave with each wave having an identical starting phase

triangular waves

a complex periodic wave resulting from the summation of odd multiples of the fundamental frequency each that have identical starting phases, decrease at a rate of 12 dB per octave

-at the level of the vocal folds you produce a triangle wave, what you hear is actually a square wave

white/gaussian noise

sound characterized by equal energy at all frequencies at which it is composed

transient

a sound that is so abrupt it does not have the opportunity to repeat itself over a cycle of vibration

continuous amplitude spectrum

various concentrations of energy

spherical propagation

travels outward from the source simultaneously in all directions

Inverse square law

there is an orderly relationship between the decrease in sound amplitude and the distance it travels from the source at a given distance from the source, sound amplitude is inversely proportional to the square of the distance from the point of measure

sound absorption

whenever sound enters or hits a barrier it turns into thermal energy

sound reflection

the sound is defelected and prolonged

reverberation

the continuation and prolongation of the original sound in a confined space

reverberation time

the time required within the environment for the reflected sound to be attenuated by 60 dB

Effects of long reverberation time

outgoing wave is going to hit the reverberating wave and cause destructive interference or speech smearing which makes the sound hard to understand

Contrast sound absorption and reflection

have an inverse relationship, as the absorption of a barrier increases its reflection decreases and its reverberation time becomes shorter. as the absorption of a barrier decreases its reflection increases and its reverberation time increaes which leads to possible speech smearing

damping

the attenuation or diminishnment as a function of time

low damped systems

the vibration or sound system occurs for a low period of time and its amplitude is diminished fairly gradually

high damped systems

the vibration or sound is very brief, very sharp decreas in amplitude

critically damped systems

the vibration stops so quickly the energy plays very little part with the environment, very little sound energy in the atmosphere

When discussing modifications of a vowel’s formant structure by the vocal tract, we
must be aware that the third (3rd) formant is most responsive to alterations of
(a)____________ of the oral cavity, the first (1st) formant is most responsive to changes in
(b)____________, and the second (2nd) format is most responsive to variations of
(c)____________.

a.) front vs back constriction

b.) mouth opening

c.) size of the oral cavity

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

A sound source initiates or creates the sound energy (1), whereas a resonator vibrates in sympathy to reinforce specific frequencies (1)

free vibration

occurs when the single application of an external force
causes an object to vibrate at its natural/resonant frequency

forced vibration

an object vibrates at a rate as dictated by the frequency of the external source of vibration

How does the amplitude of a frequency change the closer it gets to the resonator’s natural frequency?

It increases/becomes greater

Resonance

frequency selective reinforcement of sound energyn

Harmonics that are close to the vocal tract’s resonant frequencies will be ____________.

reinforced or made louder

The harmonics of the glottal sound wave decrease at a rate of ____________ per octave

-12 dB

Explain what happens to the amplitude of the applied force deviates greatly from the natural frequency of the resonator.

It is attenuated/ becomes smaller

Explain what is meant when the vocal tract is described as a “variable resonator.”

Every time an articulator is moved there is a change to the volume, shape, and length of the vocal tract, thereby altering/changing the resonant frequencies of the vocal tract

If the vocal tract is considered as a tube closed at one end and open at the other, the ____________ are considered the closed end

vocal folds

Without the supralaryngeal system, our phonology would be extremely limited, particularly for the production of ____________.

vowels

Why is the vocal tract considered a filter?

It allows certain frequencies to pass through with greater amplitude, while attenuating or reducing others

Natural/Resonant Frequency

The frequency at which an object vibrates with the least amount of effort

Explain what is meant when the vocal tract is described as a “broadly tuned resonator.”

The vocal tract will reinforce a range of frequencies around the resonant frequency

Harmonics that do not approximate the natural frequencies of a resonator or are beyond its “cut off” limits will be ____________

Attenuated/Reduced

The resonance characteristics of a uniform tube, closed at one end and open at the
other, can be mathematically calculated using the ____________.

odd quarter wavelength rule

Resulting from a (a)____________ created by the way the lips open into the
atmosphere, the (b)____________ is, per Fant’s theory, the final modification of a speech
sound and is modeled as a (c)____________ per octave increase in amplitude

a.) baffle effect

b.) radiation characterisitc

c.) +6 dB

Per Fant’s theory, a phoneme is shaped by the vocal tract via the interplay of three
functions. The (a)____________ function represents the sound as it enters the atmosphere
after having been completely/fully shaped by the entire vocal tract, including the lips.
The (b)____________ function occurs at the level of the vocal folds. The (c)____________
function is not a sound, but rather the process of modification the sound undergoes as it
travels through the vocal tract.

a) Output

(b) Source

(c) Transfer

The vocal tract can be modeled as a uniform tube that is ____________ at one end and ____________ at the other.

closed/open

What is a formant?

Concentrations of energy at specific frequencies that have been reinforced by the resonator

Why does a tuning fork’s vibration decay over time even if it is not touching a barrier?

Because of the resistance offered by the air/Damping

Resonators do not ____________ energy, but rather only reinforce frequencies consistent with their physical characteristics

initiate

Explain what the supralaryngeal cavity is

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

Sound as produced at the level of the larynx approximates a ____________ in shape

triangle

What does the odd-quarter wavelength rule say/state?

The air in a uniform tube closed at one end and open at the other will resonate to a frequency 4 times the length of the tube, with resonant frequencies occurring at odd-numbered intervals

Describe the sound produced by the vocal folds before it is influenced by the supralaryngeal cavity.

A quasiperiodic triangle wave that sounds like a flat, low volume buzz.

Because everything in nature vibrates, anything can be a source, medium, and/or ____________

resonator

In the production of voice consonants, the interaction between the front and back cavities is known as ____________.

coupling

After filtering, what remains the same between the glottal sound and the sound that emerges from the lips?

The fundamental frequency and the harmonics.

a) Identify the sound sources for a voice consonant, indicating which is primary and
which secondary. (b) Identify the sound source for voiceless consonants. (c) Explain how
the length of the front/anterior cavity influences the resonant shaping of consonants (be
explicit in your explanation

(a) Primary - vocal folds, Secondary- point of constriction/obstruction of articulators

(b) Point of constriction/obstruction of articulators

(c) The larger the front cavity, the lower its resonant frequency and the more shaping provided --- The shorter front cavity, the higher resonant frequency and the less shaping provided.

A resonator can be forced to vibrate at frequencies other than its natural frequency, however, the reinforcement will be ____________.

Less/Minimal

acoustic resonator

anything that contains air

velocity constant

34,300 cm/sec

Odd quarter wavelength formula

F1: (velocity x1 )/ (4x length of tube)

F2: (velocity x3)/ (4x length of tube)

F3: (velocity x5)/ (4x length of tube)