question: Why does the sound of a bottle/glass being filled with a liquid change as it gets fuller?
comment: There is less room in the top of the container for the sound to resonate (echo). Smaller areas will create a higher pitch. Edit: grammar
passages: Temporal Theory posits that the cause is from looking at the phase locking to tell what the pitch is. This theory has a hard time explaining diplacusis. There are some examples of pitch which don’t have an "edge" on the basilar membrane, which this would account for—i.e. white noise, clicks, etc. (need a reference)
   Concurrent with his membrane work, Culkin was helping to develop a mechanically resonating loudspeaker with the founders of Velodyne Acoustics. Culkin married these two areas of expertise and struck out to overcome membrane fouling through the use of vibration.
  
  The first VSEP prototype Culkin developed was a literal combination of loudspeaker and membrane technology as the photo shows below.
  
  Section::::Principle of operation.
   In fluids, only the medium's compressibility and density are the important factors, since fluids do not transmit shear stresses. In heterogeneous fluids, such as a liquid filled with gas bubbles, the density of the liquid and the compressibility of the gas affect the speed of sound in an additive manner, as demonstrated in the hot chocolate effect.
   BULLET::::2. A small jet of water perturbs the surface to introduce air bubbles.
  
  BULLET::::3. A rapidly formed vapor cavity via focused laser pulse.
  
  The standing acoustic wave, which contains pressure antinodes at the center of the containment vessel, causes the bubbles to quickly coalesce into a single radially oscillating bubble.
  
  Section::::Bubble surface.:Collapse.
   Section::::Device Operation.:Inherent Functionality.
  
  The structure of the basic surface acoustic wave sensor allows for the phenomena of pressure, strain, torque, temperature, and mass to be sensed. The mechanisms for this are discussed below:
  
  Section::::Device Operation.:Inherent Functionality.:Pressure, Strain, Torque, Temperature.
   The inadequacies of this conclusion, however, were pointed out by Frenkel in his revision of the kinetic theory of solids and the theory of elasticity in liquids. This revision follows directly from the continuous characteristic of the structural transition from the liquid state into the solid one when this transition is not accompanied by crystallization—ergo the supercooled viscous liquid. Thus we see the intimate correlation between transverse acoustic phonons (or shear waves) and the onset of rigidity upon vitrification, as described by Bartenev in his mechanical description of the vitrification process.
   BULLET::::- Clements, G. N., 1990. "The Role of the Sonority Cycle in Core Syllabification." In John Kingston & M. Beckman, eds., "Papers in Laboratory Phonology I", Cambridge: Cambridge University Press, Cambridge, MA, pp. 283-333
  
  BULLET::::- Clements, G. N. & Elizabeth Hume, 1995. "The Internal Organization of Speech Sounds" In John Goldsmith, ed., "Handbook of Phonological Theory". Oxford: Basil Blackwell, Oxford, pp. 245-306
  
  BULLET::::- Clements, G. N., 2003. "Feature Economy in Sound Systems", "Phonology" 20.3, pp. 287-333
   Section::::Factors.:Intensity.
  
  Only when the intensity of the noise replacing the phonemes is the same or louder as the surrounding words, does the effect properly work. This effect is made apparent when listeners hear a sentence with gaps replaced by white noise repeat over and over with the white noise volume increasing with each iteration. The sentence becomes more and more clear to the listener as the white noise is louder. 
  
  Section::::Factors.:Dichotic listening.
   The second biggest factor that affects drum sound is head tension against the shell. When the hoop is placed around the drum head and shell and tightened down with tension rods, the tension of the head can be adjusted. When the tension is increased, the amplitude of the sound is reduced and the frequency is increased, making the pitch higher and the volume lower.
   The SOFAR channel is centred on the depth where the cumulative effect of temperature and water pressure (and, to a smaller extent, salinity) combine to create the region of minimum sound speed in the water column. Near the surface, the rapidly falling temperature causes a decrease in sound speed, or a negative sound speed gradient. With increasing depth, the increasing pressure causes an increase in sound speed, or a positive sound speed gradient. 
   Turbulence, foam, steam, chemical mists (vapors), and changes in the concentration of the process material also affect the ultrasonic sensor’s response. Turbulence and foam prevent the sound wave from being properly reflected to the sensor; steam and chemical mists and vapors distort or absorb the sound wave; and variations in concentration cause changes in the amount of energy in the sound wave that is reflected back to the sensor. Stilling wells and waveguides are used to prevent errors caused by these factors.
   Section::::Animal sounds.
   The steady flow from a circular orifice can be converted to an oscillatory flow by adding a downstream plate with a circular hole aligned with the orifice. Small perturbations in the flow feedback to the orifice to cause a variable volumetric flow rate through the downstream hole because of the symmetry of the feedback.
   One factor is found in the variable oxygen transmission rate (OTR) of cork stoppers, which translates to a degree of bottle variation.
   The behavior of sound propagation is generally affected by three things:
  
  BULLET::::- A complex relationship between the density and pressure of the medium. This relationship, affected by temperature, determines the speed of sound within the medium.
   For the 1966 paper that made the question famous, Kac was given the Lester R. Ford Award in 1967 and the Chauvenet Prize in 1968.
   The inherent functionality of a surface acoustic wave sensor can be extended by the deposition of a thin film of material across the delay line which is sensitive to the physical phenomena of interest. If a physical phenomenon causes a change in length or mass in the deposited thin film, the surface acoustic wave will be affected by the mechanisms mentioned above. Some extended functionality examples are listed below:
  
  Section::::Device Operation.:Extended Functionality.:Chemical Vapors.
   BULLET::::2. The bubble contents obey the ideal gas law
  
  BULLET::::3. The internal pressure remains uniform throughout the bubble
  
  BULLET::::4. No evaporation or condensation occurs inside the bubble
  
  The fifth assumption, which changes between each formulation, pertains to the thermodynamic behavior of the liquid surrounding the bubble. These assumptions severely limit the models when the pulsations are large and the wall velocities reach the speed of sound.
  
  Section::::Bubble dynamics.:Keller-Miksis formulation.
   Section::::Description.
   Section::::Awards.
  
  "El ruido de las cosas al caer" won the 2011 Alfaguara Prize.
   With liquids containing solids, similar phenomena may occur with exposure to ultrasound. Once cavitation occurs near an extended solid surface, cavity collapse is nonspherical and drives high-speed jets of liquid to the surface. These jets and associated shock waves can damage the now highly heated surface. Liquid-powder suspensions produce high velocity interparticle collisions. These collisions can change the surface morphology, composition, and reactivity.
  
  Section::::Sonochemical reactions.
   Section::::Device Operation.:Inherent Functionality.:Mass.
  
  The accumulation of mass on the surface of an acoustic wave sensor will affect the surface acoustic wave as it travels across the delay line. The velocity "v" of a wave traveling through a solid is proportional to the square root of product of the Young’s modulus "E" and the density formula_2 of the material.
   Jugs will also produce sound at their main resonance frequency when air is blown across the top opening. This method is not used in bands, since it is relatively quiet and produces only a single pitch. It is typically used for making glass bottles whistle. A larger bottle produces a lower musical pitch while smaller ones produce higher pitches. The pitch of a bottle played in this way may be controlled by changing its volume by adding or emptying contents. Loudness is a function of the speed of the air blown across the top.
  
  Section::::History.
   the dispersion of incoming sound waves to separate frequencies spatially. In brief, the membrane is tapered and it is stiffer at one end than at the other. Furthermore, sound waves travelling to the far, "floppier" end of the basilar membrane have to travel through a longer fluid column than sound waves travelling to the nearer, stiffer end. Each part of the basilar membrane, together with the surrounding fluid, can therefore be thought of as a "mass-spring" system with different resonant properties: high stiffness and low mass, hence high resonant frequencies at the near end, and low stiffness and high mass, hence low resonant frequencies, at the far end. This causes sound input of a certain frequency to vibrate some locations of the membrane more than other locations. As shown in experiments by Nobel Prize laureate Georg von Békésy, high frequencies lead to maximum vibrations at the basal end of the cochlear coil, where the membrane is narrow and stiff, and low frequencies lead to maximum vibrations at the apical end of the cochlear coil, where the membrane is wider and more compliant. This "place–frequency map" can be described quantitatively by the Greenwood function and its variants.
   Tuned bottles
  
  Tuned Bottles are musical instruments in the percussion family; they are found objects which are subsequently filled with water to create different pitches.
  