Quiz 2/Final: General Flashcards
Sharply versus Broadly tuned resonators
- Sharp Tuning:
- system responds to a small range of frequencies
- vibration persists for a long time (low damping)
- examples: tuning fork, crystal glass
- Broad Tuning:
- system responds to a larger range of frequencies
- vibration dies out quickly (heavy damping)
- examples: sound in air, phone earpiece
What are the two types of sound source?
- A: phonatory/subglottal source: vibration of vocal folds at the glottis, periodic (AKA vowels)
- B: supraglottal source: air passes through larynx to upper vocal tract (mouth) where airstream is modified, aperiodic (aka unvoiced consonants)
How do source and filter relate?
-whether the source is subglottal (glottis) or supraglottal (mouth), the sound is filtered by the resonant frequencies of the vocal tract
Source and filter: specifics in voiced speech
- At any given time in the production of a vowel, the spectrum of the sound radiated from the lips can be found from the product of
- the excitation (source) spectrum generated by the larynx
- the frequency response (filter) of the vocal tract configuration
- In voiced speech:
- fundamental frequency (perceived as vocal pitch) is a characteristic of the glottal source
- features such as vowel formants are characteristic of the vocal tract filter (resonances)
- Any change of vocal tract configuration alters the frequencies at which the cavities resonate
- Size and length of the vocal tract also alters the frequencies at which the cavities resonate
Source and filter: Independence of source and filter, clinical populations
- you hold the source constant while changing the filter to:
- maintain constant pitch (f0)
- vary vowel (eg change from [i] to [u])
- you hold the filter constant while changing the source to:
- articulate a single vowel (eg [i] in isolation)
- vary f0 (eg from low to high pitch)
- How does this relate to clinical populations:
- a client’s speech disorder can often be isolated to the source or the filter
-Any vowel sound produced is a product of vocal fold vibration (the source) and the resonances of a particular vocal tract shape and length (the filter)
Acoustic Resonators Relative to Speech and Hearing:
- Vocal Tract:
- both air filled and closed at one end
- the closed end of the vocal tract is the vocal folds for voiced sounds
- Ear Canal:
- the closed end is the eardrum
Resonating Cavities of the Vocal Tract
- all of the air cavities above the larynx from the glottis to the lips
- Large resonating cavities: pharyngeal, oral, and nasal cavities
- Small resonating cavities: air spaces between the lips, between cheeks and teeth, and within the larynx and trachea
What factors are involved in the resonation of air filled tubes? (4 things)
- Air filled tubes resonate at specific frequencies depending on:
- 1: whether it is open at one or both ends
- 2: its length
- 3: its shape
- 4: the size of its openings
How do large and small resonating cavities differ?
- the larger the resonating cavity (vocal tract), the LOWER the frequencies to which it will respond
- the smaller the resonating cavity (vocal tract), the HIGHER the frequencies to which it will respond
How do you solve for R1 of a male vocal tract?
- The lowest natural frequency at which a tube resonates has a wavelength (λ) four times the length of the tube
- Given: average vocal tract length (L) of 17cm;
- λ = 4(L)
- solve for λ: λ = 4(17cm) = 68cm
- λ = 68cm
What is the relationship between pressure and velocity in the vocal tract/resonating tube?
Air pressure and air particle velocity in resonating tube are inversely related:
- Closed end (glottis)
- air pressure is at a maximum
- air particle velocity must approach zero
- Open end (lips)
- air pressure is at a minimum
- air particle velocity must be at maximum
What are the major differences between vowel and consonant production? (source, filter)
- Constrictions used to produce sounds are usually more extreme than those for vowels
- various configurations of the vocal tract generate different combos of resonant frequencies (formants) for each sound
- Differences in the ways the sources of sound are used in the production of consonants
- vowels usually produced only w/ periodic sound source, consonants may use aperiodic or combo
What is a formant?
- a peak of resonance in the vocal tract
- the vocal tract acts as a resonator with frequencies which can be modulated by the articulators, forming the vocal formants which make vowel sounds recognizable
- formants are synonymous with resonant frequencies: R1=F1
Why do absolute formant values differ across speakers?
- speakers differ in overall tract-length
- parts of the vocal tract may vary in size: the pharynx is proportionally smaller in women
- speakers of the same language vary in dialect and idiolect (dialect unique to individual)
When is pressure at maximum and minimum?
- Air pressure is at maximum at the closed end (glottis)
- Air pressure is at minimum at the open end (lips)
- THIS IS INVERSE TO VELOCITY
