Quiz #2

Lecture 8-10

Descriptive Research

Descriptive Research

Observation of unmanipulated behavior

Experimental Research

Experimenter seeks to affect behavior b applying one or more experimental (independent) variable

Waveform Editing

• Digitized natural speech

• where the amplitude of the signal at each point in time is plotted against time.

• Speech does not sound mechanical or artificial, natural characteristics of speech (e.g., intonation, rhythm, and timbre of the speaker's voice) are preserved

Synthetic Speech

Computer-generated speech; sometimes refers to as text-to-speech

What is waveform analysis used for?

Used for: Pressure/amplitude changes

Uses: identifying individual phonemes, measuring vocal tract characteristics, and detecting speech disorders

What does waveform display

• Changes of air pressure over time

• Complexity of the acoustic patterns

• (Where is the amplitude and where is the pressure)

Spectral Analysis

Spectrograms

What is a Spectrogram used for?

Visual representation of frequency changes of a speech signal over time; Can be used for speech analyses and research (e.g., detecting speech disorders, and measuring the timing and rhythm of speech)

Narrow-band spectrogram

• Displays narrow range of frequencies (i.e., between 0 and 4000 Hz)

  • Purpose: Speech analysis in this frequency range.

Wide-band Spectrogram

• Displays a broader range of frequencies (i.e., typically between 0 and 20,000 Hz or higher)

  • Purpose: Analyses of complex sounds (e.g., music or natural sounds, which may contain frequency components across a wide range)

Narrowband amplitude spectrum

• Provide analysis of the amplitude of a sound signal within a narrow frequency range

• Purpose: speech analysis and research to analyze the spectral characteristics of speech sounds

Wideband amplitude spectrum

• provide a general analysis of the amplitude (i.e., the strength or intensity) of a sound signal across a wide range of frequencies.

EMG (what it measures and what its used for)

• Measures electrical activity of neural signals to muscles

• valuable tool for speech analysis

  • Yields information about the muscle activity and motor control involved in speech production

  • Can be used to study different aspects of speech, including articulatory movements, coarticulation etc.

Spirometer and pneumotachography(what it measures and what its used for)

• measures airflow during nonspeech tasks

• Air-Flow during speech usually collected via face mask (pneumotachograph)

• Divided masks may be used to assess oral versus nasal airflow

Nasometer (what it measures and what its used for)

• measures the amount of sound energy emitted from the nose during speech

  • Used assess and treat speech disorders related to nasality, such as hypernasality or hyponasality.

Pneumography

• Measure changes in lung volume and airflow during breathing → useful to assess respiratory function during speech → important for diagnosing and treating speech disorders related to breathing

Laryngoscopy

• Examine the inside of the larynx and surrounding structures (e.g, vocal cords) with a laryngoscope

• Two Types: Indirect & Direct Laryngoscopy

• Used to diagnose/treat a variety of speech disorders (e.g., vocal cord nodules, polyps, or cancer); can also be used to evaluate vocal function and to assess the effects of voice therapy or surgical intervention.

Indirect Laryngoscopy

non-invasive procedure that involves the use of a small mirror and a light source to visualize the larynx through the mouth

Direct Laryngoscopy

more invasive procedure that involves the use of a rigid or flexible laryngoscope to visualize the larynx and surrounding structures through the mouth or nose

Fiberoptic endoscopy

• Light source and camera are introduced through nose into laryngopharynx (larynx, pharynx, and upper airway)

• Used to diagnose/treat various disorders such as vocal cord nodules, polyps, or cysts, laryngitis or other inflammation of the larynx, laryngeal cancer swallowing disorders (dysphagia), upper airway obstruction or stenosis, chronic cough etc.

Ultrasound

• Inaudible, high frequency sound waves are passed into tissues

• Waves reflect upon hitting an air boundary (e.g., in the oral cavity)

• Reconstructed echo pattern shows shape of structure(s)

• Used to assess the movement and position of the tongue, lips, and other articulators during speech  important for diagnosis and treatment of various speech disorders (e.g., articulation disorders, apraxia of speech, dysarthria, resonance disorders such hypernasality or hyponasality, dysphagia, etc.)

Palatography(what it measures and what its used for)

• Measures contact between tongue and palate

• Ex: EPG

• Can be used to diagnose and treat articulation disorders

what does MRI stand for?

Magnetic resonance imaging

MRI (what it measures and what its used for)

• Can be used for identifying brain regions involved in speech

• examining structural abnormalities associated with speech disorders, such as cerebral palsy, stroke, and traumatic brain injury

Methods more easily incorporated into clinical use ___ ( 3)

• Ultrasound

• Pneumography

• Palatography

Resonance

• occurs when an object or system vibrates at a certain frequency that matches the natural frequency of another object or system nearby. This causes the second object or system to vibrate with greater amplitude or intensity, amplifying the original vibration

• Resonance is reaction to sound

• Ex: pushing a swing

What are the sound sources of speech

Phonatory/ Subglottal source & Supraglottal source

Phonatory / Subglottal source

vibration of vocal folds at the glottis; periodic (e.g., vowels

Supraglottal source

Air passes through larynx into upper vocal tract (mouth) where airstream is modified; aperiodic (e.g., some consonants like /f/, /p/)

How do we alter the spaces within the human vocal tract?

By movement of the articulators

• Tongue, pharynx, palate, lips, and jaw

Resonances of the vocal tract are called ____.

formants

Whether the source is subglottal (glottis) or supraglottal (mouth), _________________________________________.

the sound is filtered by the resonant frequencies of the vocal tract

Large Resonating Cavities

pharyngeal, oral, and nasal cavities

Small Resonating cavities

air spaces between the lips, between the teeth and cheeks, and within the larynx and trachea

Oral Cavity

• Formed by the space between the teeth, upper and lower jaws (maxilla, mandible), and tongue

Major oral landmarks for speech:

• Teeth (especially incisors): Production of dental sounds such as [t d]

• Alveolar ridge: Anterior region of hard palate; production of alveolar sounds such as [t d n s]

• Velum (soft palate): Production of velar sounds such as [k g ŋ]

Speech, language, & instrumentation

• Instruments can measure many things:

  • Muscular activity

  • Movements associated with respiration, phonation, and articulation

  • Structures involved in speech (e.g., the vocal tract) and language (e.g., the brain)

  • Nervous system activity during speaking and listening

velum ( soft palate)

• Closes the velopharyngeal (VP) port

• Separates nasal and pharyngeal cavities

• Used for oral speech sounds

t/f the tongue consists of extrinsic and intrinsic muscles.

true

t/f The velum is Lowered for oral sounds and higher for nasal sounds.

false, Lowered for nasal sounds and higher for oral sounds!

What does F1 stand for?

Tongue height/mouth opening

What does F2 stand for?

Tongue placement in oral cavity

Source, Filter, & Speech

• Speech mechanism is a combination of source (vocal fold vibrations) and filter (resonant response of the supraglottal vocal tract; shaping of mouth for sound waves)

• At any given time in the production of a vowel, the spectrum of the sound radiated from the lips can be attributed to the source (vibrations) and the filter (shaping)

power, source, filter

power: the lungs

source: vocal tract

Filter: articulation for each sound

Relative Speakers

patterns of formant values are consistent across speakers; for example, [i] has a low F1, and a high F2

Absolute Speakers

• formant values vary across speakers:

  • Speakers differ in overall vocal-tract length

  • Parts of the vocal tract may differ in size: The pharynx is proportionally smaller in women than men

  • Speakers of the same language vary in dialect

Traditional classification based on impressions of articulation:

• Tongue shape

• tongue position

• Lip posture

Vowels in Clinical Populations

• Congenitally deaf speakers often have deviant vowel spaces:

  • Jaw and tongue placements are more constrained than in hearing speakers

  • The range of formant values is not as great as in hearing speakers

• Impaired vowel production may be evident in apraxia of speech, dysarthria, and cerebral palsy

• Foreign accents may involve errors in vowel production

• Visual feedback (e.g., via spectrograms) may help speakers improve vowel production

Tense Vowels

• (e.g., [i e o u]):

  • Involve more extreme articulations

  • Have longer durations

  • Can occur in open syllables (e.g., CV)

Lax Vowels

• [e.g., ε ʌ ʊ]

  • Have less extreme articulatory postures

  • Are shorter in duration

  • Occur only in closed syllables (e.g., CVC)

How are constant sounds different?

• Differences in the source and filter:

• Constrictions used to produce consonants are usually more extreme than those for vowels

• Various configurations of the vocal tract generate different combinations of resonant frequencies (formants) for each sound

• Differences in the ways the sources of sound are used in the production of consonants

Difference between voice (periodic)and voiceless (aperiodic)sounds?

• is the presence or absence of vocal fold vibration during their production.

Examples of Voiced Sounds

/b/, /d/, /g/, /v/, /z/, /l/, and /m/

Examples of voiceless sounds

/p/, /t/, /k/, /f/, /s/, /ʃ/, and /θ/ (as in "thin")

oral sounds

• produced by creating a constriction in the oral cavity, or mouth; this constriction blocks or modifies the flow of air as it moves through the mouth, resulting in different sounds

• includes: stops; fricatives ; affricatives

  • Soft palate elevated against posterior pharyngeal wall

  • Velopharyngeal (VP) port closed

  • Levator palatini muscle active

  • Degree of VP closure varies with phonetic context

Nasal Sounds

• produced by lowering the soft palate to allow air to flow through the nasal cavity as well as the mouth, resulting in a different sound quality.

• Nasals and the velum

  • Require open VP port (lowered velum):

  • Levator palatini muscle is relaxed

  • Palatoglossus muscle may actively lower velum

  • Nasal cavities form a resonant chamber

  • At the lips [m]

  • At the alveolar ridge [n]

  • At the soft palate [ŋ]

2 constant types

Sonoranta & Obstruents

sonorants

• are a group of speech sounds that are produced with a relatively open vocal tract, allowing for the free flow of air through the mouth.

  • Nasals

  • Liquids

  • Glides

Obstruents

• are a group of speech sounds that are produced by creating a constriction or obstruction in the vocal tract

  • Stops

  • Fricatives

  • Affricatives

Fricatives can be formed in what places?

• Labiodental [f v]  few / view

• Linguadental [Ө ð]      bath / bathe

• Alveolar [s z]  sue / zoo

• Postalveolar [∫ 3]  shy / leisure

How are stops produced?

• by a complete closure of the vocal tract, followed by a sudden release of air

  • Examples include /p/, /b/, /t/, /d/, /k/, and /g/

obstruents in clinical populations

• Hyponasality or hypernasality may result from problems with velopharyngeal (VP) control:

  • Cleft palate

  • Motor speech disorders

• Poor control of VP mechanism may impair production of oral obstruents that require buildup of intraoral air pressure

• Problems of interarticulator timing in motor speech disorders may affect VOT and stop voicing contrasts

4 elements of prosody

• Stress

• intonation

• duration

• juncture

factors that impact duration:

• Intrinsic duration: Some sounds are naturally longer than others (e.g., diphthongs are longer; lax vowels are shorter)

• Phonetic context: For example, vowels preceding voiced consonants are longer in duration than vowels preceding voiceless consonants: Compare the /i/ vowels in “leaf” and “leave”

• Syllables at the end of a major syntactic unit display what is called phrase-final or pre-pausal lengthening

Stress

the degree of emphasis on individual syllables within words

Intonation

• Provides information on speaker affect: Extreme f0 changes associated with heightened emotion

• can differentiate question vs statements

Juncture

the way sounds are joined to (or separated from) one another

Narrowband or wideband spectrogram??

Wideband

Narrowband or wideband spectrogram??

Narrowband

Narrowband ampltiude or Wideband amplitude spectrum?

Narrowband ampltiude

Narrowband ampltiude or Wideband amplitude spectrum?

Wideband amplitude spectrum