Sound, Resonance Flashcards
What is the speed of sound?
approximately 1130 feet or 345 meters per second
The concept of frequency was first proven in experiments by whom?
Marin Mersenne (1588- 1648), the French physicist and musical theorist.
What percentage of a singer’s energies generally is converted into actual sound?
One.
What are sound waves?
alterations in pressure which propel themselves through an elastic medium (in singing, elastic medium is air)
2 phases of a sound wave
Compression phase / increased pressure, leaving behind…
Rarefaction phase / decreased pressure
Slowest and fastest points in a sound wave?
Slowest speed occurs at the two extreme positions
Fastest speed occurs at the median of its oscillation
3 Properties of musical sound
Frequency
Amplitude
Timbre
Frequency is…
# of vibratory cycles per second 2 measurements: CPS=cycles per second Hz=hertz
What is a period?
time taken to complete one vibratory cycle
Wave length
Distance traveled in one complete vibratory cycle
speed of sound (1130 ft or 345 meters/second) / frequency of the wave
Pitch
the mind’s interpretation of frequency
The EAR has max frequency and amplitude sensitivity between…
50 Hz and 4000 Hz
Amplitude
max displacement from a rest position
Loudness
ear’s subjective evaluation of a sound wave’s amplitude
Sound intensity
sound power per unit area (watts/m2 or cm2)
Decibels
ratio of given intensity (I) to threshold of hearing (threshold = 0 decibels) (labeled as dB)
Sound pressure
(measured as SPL) local pressure deviation as compare with atmospheric pressure (caused by a sound wave)
Timbre
(tone quality) - quality of a musical note, sound, or tone that distinguishes different types of sound production
Timbre is determined by these 6 things…
of partials
Distribution of partials
Relative intensity (strength) of partials
Inharmonic partials (not even multiples of F0 (fundamental))
Fundamental Tone
Total intensity
Damping
time rate at which energy is dissipated in a vibrating body
Interference
effect produced by superposition of 2 or more systems of waves in which these waves reinforce, neutralize, or in other ways interfere with each other
Constructive Interference
Waves are in phase
Destructive Interference
Waves are out of phase
What sets singing apart? (4)
- Sound wave produced is a saw-tooth type containing the fundamental and its harmonics
- The harmonic output (sound wave) of the vocal cords can be varied to some extent (contact time, aerodynamic power, length of folds, mass of folds, etc.)
- The F0 of the wave can be varied over at least 2 octaves
- Vocal cavities possess several different discrete or distinct resonant frequencies which can be varied, i.e. certain overtones can be accentuated
4 Acoustic Laws Concerning Cavities
- Volume - the larger the cavity, the lower the frequency at which it resonates. The smaller the cavity, the higher the frequency.
- Size of aperture - the longer and narrower the neck of the opening, the lower the frequency to which the cavity responds. The wider and flatter the neck, the higher the frequency to which it responds.
- Texture of the walls - the softer the walls, the more lower harmonics are emphasized. The harder the walls, the more the higher harmonics are emphasized.
- Conductivity factor - coupling of the resonators can enhance the acoustic information generated at the source (vocal folds)
According to C. Culver…“The unique feature of the vocal apparatus is…”
“that the size and shape of the resonant system is under the conscious control of the speaker or singer.”
3 ways voice most similar to a reed instrument…
- Breath
- Vibrating folds (like a double reed)
- Resonating cavities
3 elements determine F0:
- tension
- thickness
- length
2 principle resonance cavities:
- Pharynx (laryngo-, Naso-, and oro-)
2. Mouth
3 parts of Pharynx
- laryngo-
- Naso-
- oro-
PHARYNX
Irregularly shaped tube - from back of nose to posterior surface of the base of the cricoid
3 Sections:
Nasopharynx
base of skull to the soft palate - palate can close off this area (eustacian tube has opening into this area)
Oropharynx
soft palate to top of epiglottis
has greatest capacity for altering its shape
Tongue position has major effect on this space and its coupling with the mouth cavity
Laryngopharynx
top of epiglottis to base of cricoid
Important with regard to resonance as sound waves pass through this area first
T/F? Chest and sinuses are resonators.
Chest, head, nose, and sinuses are not true resonators
According to Garcia: “the real mouth of the singer ought to be considered the…”
Pharynx
One major cause of pharyngeal constriction
disuse of extrinsic musculature
According to W. Shakespeare, “The quality of the vowel has its origin in…”
“…the freedom of the space behind and above the tongue and in the freedom of the tongue itself.”
Zemlin’s 3 Articulatory Motions that Shape Vocal Tract
- Location of major constriction along the length of vt (where hump of tongue is)
- Degree of constriction (space from tongue to roof of mouth)
- Length of vocal tract (influenced by larynx and lip rounding/spreading)
2 Palatal Depressors
- Glosso-palatine. Runs from the front surface of the soft palate to insert in the sides of the tongue. Also called the anterior palatine arches or faucial pillars.
- Pharyngo-palatine. Runs from the soft palate downward to blend with the stylo- pharyngeal muscle and then into the side walls of the pharynx. Also called the posterior palatine arches or faucial pillars.
3 Palatal elevators and tensors
- Levator palatine. Forms the bulk of the soft palate. Arises from the temporal bone and the cartilaginous framework of the Eustachian tube and inserts in the palatine bone. Lifts the soft palate upward and backward and is important to velo- pharyngeal closure.
- Tensor palatine. Contracts laterally and flattens, tenses, and slightly lowers the soft palate.
- Uvular muscle. Lifts the uvula, a midline pendulous structure, and with it the soft palate. Arises from the palatine bone, runs posteriorly the length of the soft palate, and inserts into the uvula.
What did Zemlin called the Fauces?
“the port through which the oral cavity communicates with the pharngeal and nasal cavities.”
Raising cheeks
seems to have effect on resonating space - helps obtain max stretch of soft palate without over-taxing the palatine arches.
Basic color (of timbre) influenced by:
- Body structure
- Vocal fold size and configuration
- Supra-glottal resonance characteristics
Percentage of Glottal Closure Time determines amplitude of vibration and with it, the character of the sound wave HOW?
More closure time = stronger higher partials; less closure time = weaker higher partials
2 major coloring devices
- Vocal folds (ringing vs. veiled)
2. Resonance tube (bright vs. dark)
What is Resonance?
a condition that exists between the source of energy and the configuration of the medium such that the energy of some frequencies of vibration will be kept alive in the medium while others will quickly die off
“Resonant Voice”
any voice production that is both easy to produce and vibrant in the facial tissues
tongue is the most important single articulator why?
because its configuration is the principal regulator of cavity coupling, for better or for worse
