You have included so many questions in this topic. So, I give an answer to one of them, "8. Does it have any relation with quantum physics?" Yes, the sound has a relation with quantum physics. Namely, A phonon, so to speak, is a quantum unit of sound. It is the lowest energy, quantized state of a vibration within a lattice structure, such as those created by the atoms of matter. For details, see the link below.

http://physics.about.com/od/physicsmtop/g/phonon.htm

Dear. Mr. Raja,

I always enjoy your questions! Thanks for this one too! 

Coming to science, you have yourself said that sound is a mechanical wave.

Here, I would add that their wavelengths range from 17 mm to 17 meters (for 20 kHz to 20 Hz, respectively).

Here, you have overlooked one fact about the term 'quantum'. This word operates and 'significantly' contributes in sub-molecular and atomic scales ONLY (please mind the term 'significantly' used by me.)

It is impossible to observe quantum events in the macro-world where we live and our day-to-day events happen. 

QUESTION -4 & 6: In purely quantum world we debate on duality (wave/particle) because in that realm ENERGY has MASS (m = E/c2). This happens because of relativity. Relativity means as you go down in size 'other' natural events which you 'ignore' or 'can not perceive' in your macro-world, become large and large as you go small and small. Electrons in motion have different masses than that when they are stationary. 

Assuming sound as particle would be a motion of particle among other particles which would 'float' and 'drift' because of buoyancy. This will even defy the well-accepted wave theory of sound itself.

QUESTION - 2: A sound wave is a method of representation and understanding behavior. It actually dose not exist. It is just a wave of forces exerted by particles to their neighboring ones.

What happens on a bicycle stand? If you shake just one bicycle of the edge you will see all of them getting tumbled. It will 'appear' to you like a wave.

An experiment for you:

Take a water bottle and fill this half with water. Measure and record its weight as accurate as you can afford to (say, on a vacuum-stored and earth motion-balanced micro-balance). Now shake this bottle until you feel sufficient and put on the same balance (in all the same conditions, obviously)

What do you see?? Do you record any 'increased' weight as the water molecules are still in motion (or have energy) given by you??

The answer is plain "NO". The reason is, WE CAN NOT OBSERVE.

Relativity does not allow us to do that.

QUESTION 10: Yes. Sound is only associated to matter. They present mechanical effects (compression, pressure, ripples etc) associated with physical state of matter.That is why we call them mechanical waves.

QUESTION 5: When a sound wave loses its energy, the lost portion is dissipated in to the friction or viscosity on the matter medium. This loss in is in form of heat generally. That is why for studying sound motion through media thermodynamics proved to be very excellent tool.

Regards,

MKD

Dear Tatsuo Tabata

Thanks for very helping and precise contributions. The concept of Phonon is associated and can be useful for understanding and further application of many metaphysical phenomenon.

Regards,

Dear dr. Raja N A Khan,

I agree with you on the fact that the relationship between perception and physical representation is elusive.  A few people are capable of seeing sounds as colors (https://en.wikipedia.org/wiki/Synesthesia). And there are means to visualize sound that don’t resort to electronics (http://people.seas.harvard.edu/~jones/cscie129/images/snd_vis/snd_vis.html). Still, physiologically, sound is related primarily to normal ear.

In my opinion one difficulty with sound is to define exactly what characteristics it has to have in order to be heard. Strong wind is a movement of air, which can be heard. Sonic boom and thunderclap are audible manifestations of air, too. Although air is needed to listen to a guitar player, and in helium gas the song music would have different tone quality and pitch, in this case apparently sound is the only “thing” propagating.

Interesting lot of questions, Raja. I'll offer my suggestions.

I think that unlike electromagnetics, there's no universal constant associated with sound. No Lorentz transformation, no singularity about its speed. And yet, it behaves similar to EM radiation, for instance with respect to reflection, refraction, diffraction, stereo effect, Doppler effect, Fourier transforms. Low frequencies bend better than high frequencies, high frequencies attenuate faster.

1 - 3. Sound is the vibration caused by alternately pressurizing and depressurizing a medium. Sound is the vibration sensed by our ears. If there were no vibration, there would be no sound. For example, a steady wind creates no sound. But a steady wind causing leaves to move, or blowing by your ear lobes, will create vibrations, which in turn produce sound. So, sound describes the effect of a vibrating medium on our ears. Unlike E&M, sound won't propagate in a vacuum.

4. No. Without vibration, there is no sound. You need that alternating pressurization and depressurization, to cause the vibration of the ear drum, and create what we call sound.

5. Sound attenuates because the vibrating medium becomes warm due to friction among molecules. The energy is dissipated as heat. Oh, same as light and RF, through a medium. (Through a vacuum, E&M attenuation is caused by diffusion, for instance the inverse square law for a point source.)

6. Phonons are merely a mathematical artifact. Since the wave behavior of sound is similar to the wave behavior of E&M, it's mathematically convenient to postulate this phonon.

7. Not just acoustics and optics, but acoustics and all E&M.

8. There is certainly similarity in the math, but aside from that, no universal constant or other magical attributes that E&M has.

9 - 11. I think those have been covered already with my suggestions for 1 - 8.

Dear Sara Liyuba Vesely

Thanks for nice contribution. Its really helping, specially about Synesthesia.

Regards

Dear Albert Manfredi

Thanks for such a nice brainstorming and providing point to point input. 

it gives many hints toward further deep down explanations.

Regards,

Estimado Raja Khan NA

Participo con gusto a esta nueva invitación, dado mi gusto por integrar las respuestas desde un punto de vista Biofísico y médico, considerando la física cuántica.

La pregunta utilizando un término compuesto y novedoso "Óptica Acústica" lanza inmediatamente mi pensamiento a la unión de conceptos y a la cuestión de ¿Como sucede esto en el mundo real y no solo mental o ideal del pensamiento?  Si la respuesta es comprensible y en el sentido afirmativo de su existencia ¿Cómo puede ser verificado este fenómeno? 

De inicio me parece factible la respuesta a la cuestión raíz ¿Óptica Acústica. El Sonido y la Física Cuántica? y a las preguntas subordinadas y didácticas para encontrar respuestas parciales, para finalmente sintetizarlas en una conclusión global e integral.

En definiciones, empiezo con el Sonido y su concepto:  Del latín sonitus, un Sonido es una sensación que se genera en el oído a partir de las vibraciones de las cosas. Estas vibraciones se transmiten por el aire u otro medio elástico. (Diccionario de la Lengua Española "DLE")

Óptica: Parte de la física que trata de la luz y de los fenómenos luminosos, como se comporta y como se manifiesta (DLE). 

La Óptica es la rama de la física que analiza las características y las propiedades de la luz, estudiando cómo se comporta y se manifiesta, considerando los fenómenos de la reflexión (la modificación que se produce en el rumbo de un rayo en la superficie que separa a dos medios, lo que hace que vuelva al punto de partida), la refracción (la alteración de dirección cuando el rayo deja un medio y pasa a otro) y la difracción (la curva aparente y la separación de la luz cuando ésta se topa con alguna barrera) son algunos de los fenómenos estudiados por la óptica. También hace referencia a todo lo que está vinculado a la Visión.

La Visión desde el punto de vista físico y biológico (Biofísico), tiene que ver con la energía luminosa; esto es "La luz o rayo de luz" en su forma corpuscular (fotones, cuantos de energía) y ondulatoria (también de acuerdo a la física relativista y cuántica)

Contemplando ambos conceptos en la síntesis (Óptica y Sonido = Óptica Acústica) y a los fenómenos ya verificados experimentalmente tanto en la La Teoría de la Relatividad como en la Física Cuántica, considero que comparten la misma característica, la de manifestarse en forma ondulatoria; pero una gran diferencia, el Sonido requiere un medio elástico como los fluidos agua y aire para propagarse en forma de ondas mecánica, con diferencias de ondulaciones y cambios de presión en dichos fluidos, para que de acuerdo con su longitud de onda y amplitud (decibel) pueda ser audible y perceptible por el oído y cerebro humano, pero la Luz no requiere este fluido ni un medio de propagación. En síntesis, Siendo la Luz electromagnética no requiere un medio ni fluidos para su propagación, ya que lo puede hacer en el vacío del espacio sideral, sin aparente merma de su energía a corto plazo, pero si cierta "dilución" o atenuación aún no cuantificada en su ruta astronómica, suponiendo que viaje hasta el fin o el inicio del universo.

Como fenómeno no solo físico, sino también biológico, es decir Biofísico, el Sonido audible para el humano tiene además de cumplir con las características ya descritas de longitud de onda y decibel, llegar al tímpano (membrana elástica que separa el conducto auditivo externo del interno), hacerlo también vibrar (serie repetida y veloz de depresiones y reposiciones de la membrana timpánica) y trasmitir dicha vibración por medio del movimiento de huesos minúsculos del oído interno, llamados yunque, martillo y lenticular, los que a su vez trasmitirán dicha vibración a una estructura denominada aparato vestibular (cóclea y conductos semicirculares) que contiene en su interior un líquido (endolinfa) que propaga y magnifica el fenómeno acústico, el cual estimula a su vez a células ciliares que transforman la energía mecánica del sonido en eléctrica, y que a su vez se trasmite así transformada al nervio acústico para que al llegar al grupo de neuronas de la corteza cerebral auditiva sensorial ( corteza cerebral temporal) se pueda integrar y hacer consciente el fenómeno de la audición (ruido, música, voz, etc) y este en posibilidad el sujeto perceptor de responder en forma congruente al fenómeno escuchado..

Finalmente tener en cuenta que el Sonido se puede propagar en forma de ondas en el aire con trayectoria lineal, o en forma de ondas en el agua en forma transversal con amplitud de menor a mayor a partir del centro. También su propagación en el aire pudiera ser de longitud de onda y decibel no perceptible para el humano pero si para oídos más finos de animales como los perros y los gatos. Independientemente de si existe cerca un oído humano o animal que lo perciba e integre a su consciencia, el Sonido puede existir siempre y cuando exista un medio fluido como los ya mencionados.

Respecto a la Óptica y específicamente en relación a la Luz, dese el punto de vista de la física, es un fenómeno electromagnético que en forma de partícula, onda o dual, se puede propagar en el vacío, sin necesidad de que exista un fluido como soporte. Esta es una gran diferencia con la propagación de las ondas sonoras. En cuanto al sentido de la Vista o Visión del humano, requiere la existencia de receptores especiales en la retina del ojo (foto-receptores) y conducción eléctrica vía nervio óptico (lineal y a saltos de la energía entre sinapsis, axones y dendritas) hasta llegar a la corteza occipital visual e integrarse (entre grupo de neuronas funcionando en red) en forma consciente como objeto o fenómeno visible o visión

Otro asunto ahora que conviene abordar, es como percibir simultáneamente ambos fenómenos Biofísicos. Esto es factible partiendo de dos órganos de los sentidos, Sonido = Oídos; y Visión = Ojos, Aún más, con frecuencia y gracias a los avances científicos y tecnológicos, se pueden ver las gráficas de sonidos y escuchar cierta reverberación lumínica; aunque por excepción, en pocas personas se pueden percibir ambos fenómenos con un sólo sentido sin mediar tecnología externa aguna, gracias a la Sinestesia. Esto significa ver sonidos u oír luz y color. Como un breviario cultural, esto es más frecuente en personas altamente creativas, ya sea científicos con tendencia y hábito de globalizar e integrar conocimientos, impresiones y razonamientos, y también en ciertos artistas muy creativos (pintores, músicos, escritores, arquitectos)

Con los planteamientos y argumentos anteriores, ya he respondido creo que a satisfacción las preguntas 1, 2 y 3. A continuación paso a responder las que en forma secuencial a su planteamiento original, considere conveniente ampliar en conceptos, ejemplos y argumentos:

• Pregunta 4. Puede el Sonido sostenerse o propagarse sin ondas. No es posible, pues requiere la presencia de un fluido como el agua o el aire para su propagación mecánica, de la forma como se ha explicado anteriormente.
• Pregunta 5. Las ondas de sonido si pierden su poder conforme se propagan en el medio fluido (aire y agua) siempre y cuando no encuentren en el camino un obstáculo que las anule o atenúe en grado extremo, o que las amplifique, por tanto se podría registrar un cambio de potencial. Por ejemplo si el Sonido se propaga por el aire y a continuación por el agua, aumenta su velocidad. Lo contrario sucede cuando la propagación cambia del agua al aire.
• Pregunta 6. Que yo sepa, una partícula como un fotón o cuanto de energía cuando se propagan electromagnéticamente en el vacío, no suenan, o la vibración ondulatoria que es simultánea a la partícula energética, no es audible por el oído humano, pero probablemente si con grandes amplificadores y simuladores de dicha vibración electromagnética.
• Pregunta 7. La Acústica y la Óptica si tienen algunos puntos en común, como se describe en argumentos anteriores respecto de coincidencias y diferencias. Por supuesto que si necesitamos profundizar más en el conocimiento profundo, conceptual y experimental de la Óptica Acústica. Ver los argumentos descritos en Biofísica de la Visión y Audición, y en el fenómeno de la Sinestesia.
• Pregunta 8.Todo lo descrito como Biofísica de la Visión y Audición (Óptica Acústica) tiene que ver con la Física Cuántica, con los detalles y argumentos ya expresados.
• Pregunta 9. El fotón si tiene relación con las ondas de sonido, cuando se propaga la Luz en forma ondulatoria.
• Pregunta 10. La magnitud y propagación del Sonido si se asocia con la materia. Hemos hablado de la propagación conocida en los fluidos aire y agua, pero también se puede propagar en sólidos "altamente resonantes" como los metales, inclusive a mayor velocidad por segundo.
• Pregunta 11. Las ondas de Sonido (y agrego a la Biofísica de la Visión) si se pueden aplicar para comprender, profundizar y desarrollar la Óptica Acústica en el futuro, con auxilio de la Mecánica Cuántica. De acuerdo con mis argumentos anteriores.

Saludos y felicitaciones tanto a colaboradores como a la coordinación de tan interesante foro de discusión y argumentación.

Atentamente

Dr. José Luis García Vigil

Dear Raja Khan NA

Gladly participate to this new invitation, given my love for integrated responses from a Biophysical and medically, considering quantum physics.

The question using a novel compound term and "Optics Acoustics" immediately launch my thought to the union of concepts and the question of How does this happen in the real world and not just mental or ideal of thought? If the answer is in the affirmative understandable and meaning of their existence How can it be verified this phenomenon?

Start it seems likely the answer to Question Optics Acoustics root. Sound and Quantum Physics? and to subordinate and didactic to find partial answers to finally synthesize them in a global and comprehensive conclusion questions.

Definition, I begin with the sound and concept: From the Latin sonitus, a sound is a feeling that is generated in the ear from the vibrations of things. These vibrations are transmitted through the air or other elastic medium. (Dictionary of the Spanish Language "DLE")

Optics: Part of physics that is light and luminous phenomena, as it behaves and how it manifests (DLE).

Optics is the branch of physics that analyzes the characteristics and properties of light, studying how it behaves and manifests, considering the phenomena of reflection (the change that occurs in the course of a beam on the surface separating two means, making return to the starting point), refraction (altering direction when the ray leaves medium and passed to another) and diffraction (the apparent curve and the separation of light when it meets with some barrier) are some of the phenomena studied by optics. It also refers to everything that is linked to the Vision.

The View from the point of view physical and biological (Biophysical), has to do with light energy; this is "light or ray of light" in its corpuscular form (photons, quanta of energy) and wave (also according to the relativistic and quantum physics)

Contemplating both concepts in the synthesis (Optical and Sound = Optical Acoustic) and phenomena and experimentally verified both in the Theory of Relativity and Quantum Physics, I believe that share the same characteristic, that of manifest as wave; but a difference, the sound requires an elastic medium such fluids water and air to spread in the form of mechanical waves with different corrugation and pressure changes in said fluids, so that according to their wavelength and amplitude (decibel ) can be heard and felt by the ear and the human brain, but the light does not require this fluid or a means of propagation. In short, being the electromagnetic light does not require a medium or fluid for propagation as it can do in the vacuum of outer space, with no apparent loss of energy in the short term, but if some "dilution" or attenuation not yet quantified in its astronomical route, assuming journey to the end or the beginning of the universe.

As no single physical phenomenon, but also biological, ie Biophysical, the audible sound for the human also has to comply with the features already described wavelength and decibel, the eardrum (elastic membrane that separates the ear canal of the inner ), do also vibrate (repeated and rapid series of depressions and reruns of the tympanic membrane) and transmit said vibration by the movement of tiny bones of the inner ear, called anvil, hammer and lenticular, which in turn will transmit this vibration a structure called vestibular apparatus (cochlea and semicircular canals) containing therein a liquid (endolymph) that propagates and magnifies the acoustic phenomenon, which in turn stimulates a hair cells that convert mechanical sound energy into electrical, and in turn thus transmitted transform the acoustic nerve to the reach the group of neurons in the auditory cortex sensory (temporal cortex) can be integrated and make aware the phenomenon of hearing (noise, music, voice, etc.) and this in the subject percipient possibility to respond to the phenomenon consistently heard ..

Finally note that the sound can propagate as waves in the air with linear path, or as waves in water transversely with amplitude low to high from the center. Also its spread in the air could be wavelength and not perceptible to the human decibel but for finer animals like dogs and cats ears. Regardless of whether there is near a human or animal ear perceives it and integrate your consciousness, the sound can always exist and where there is a fluid medium such as those mentioned.

Regarding the Optics and specifically in relation to the light, give yourself the point of view of physics, it is an electromagnetic phenomenon that shaped particle, wave or dual, can propagate in a vacuum, without need for a fluid such as support. This is a big difference with the propagation of sound waves. As for the sense of sight or vision of the human, it requires the existence of special receptors in the retina of the eye (photoreceptors) and electrical conduction via the optic nerve (linear and leaps of energy between synapses, axons and dendrites) go and integrate the visual occipital cortex (between neurons working group network) in consciously visible object or phenomenon or vision

Another issue which should be addressed now is how Biophysical simultaneously perceive both phenomena. This is feasible from two organs, Sound = ears; Eyes and Vision = even more frequently and thanks to scientific and technological advances, you can see the graphics sounds and hear some light reverb; although exception, few people can perceive both phenomena with one-way without any external technology aguna thanks to synesthesia. This means seeing or hearing sounds light and color. As a cultural breviary, this is more common in highly creative people, whether scientists tendency and habit to globalize and integrate knowledge, impressions and reasoning, and also in some very creative artists (painters, musicians, writers, architects)

• With previous approaches and arguments, I think I answered to the satisfaction questions 1, 2 and 3. Next step to answer that sequentially to its original approach, consider appropriate to extend concepts, examples and arguments:
• Question 4. Can be sustained or spread without sound waves. It is not possible, since it requires the presence of a fluid such as water or air for mechanical spread, the way as explained above.
• Question 5. The sound waves if they lose their power as they propagate in the fluid medium (air and water) as long as there are in the way an obstacle that nullifies or mitigates extreme degree, or that amplify therefore be you could see a potential change. For example if the sound propagates through the air and then by water, increases its speed. The opposite happens when the spread changes from water to air.
• Question 6. To my knowledge, a particle like a photon or quantum of energy when propagated electromagnetically in a vacuum, no sound, or the wave vibration is simultaneous to the energetic particle is not audible to the human ear, but probably if with large amplifiers and said electromagnetic vibration simulators.
• Question 7. The acoustics and optics if they have some common ground, as described in previous arguments about similarities and differences. Of course if we need to go deeper into the deep, conceptual and experimental knowledge of optics acoustics. See the arguments described in Biophysics of vision and hearing, and the phenomenon of synesthesia.
• Question 8. All described as Biophysics of Vision and Hearing (Optic Acoustic) has to do with quantum physics, with details and arguments already expressed.
• Question 9. The photon if relates to sound waves when the light propagates in a wave.
• Question 10. The magnitude and propagation of sound if it is associated with matter. We talked about the spread fluids known in air and water, but also can be spread in "highly resonant" solid as metals, including faster per second.
• Question 11. Sound waves (and added to the Biophysics of Vision) if they can be applied to understanding, deepen and develop Optics Acoustics in the future, with the aid of quantum mechanics. According to my previous arguments.

Greetings and congratulations to both partners and the coordination of this interesting forum for discussion and argument.

Sincerely

Dr. Jose Luis Garcia Vigil

Dear Dr. Jose Luis Garcia Vigil

Thanks once again for very comprehensive and helpful contribution.

Your conclusion is very true regarding significance of Acousto-Optics in future technologies;

"Sound waves (and added to the Biophysics of Vision) if they can be applied to understanding, deepen and develop Optics Acoustics in the future, with the aid of quantum mechanics. According to my previous arguments."

Yes, off course, Many Greeting to All the Kind Participants for their Valued Cooperation.

Regards,

Raja

A velued article on sound and black hole

http://www.nature.com/news/one-man-band-the-solo-physicist-who-models-black-holes-in-sound-1.20437