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Tuning Forks
A tuning fork is an acoustic resonator in the form of a two-pronged fork with the prongs (tines) formed from a U-shaped bar of elastic metal (usually steel). It resonates at a specific constant pitch when set vibrating by striking it against a surface or with an object, and emits a pure musical tone once the high overtones fade out. A tuning fork's pitch depends on the length and mass of the two prongs. They are traditional sources of standard pitch for tuning musical instruments. The tuning fork was invented in 1711 by British musician John Shore, sergeant trumpeter and lutenist to the royal court. Description A tuning fork is a fork-shaped acoustic resonator used in many applications to produce a fixed tone. The main reason for using the fork shape is that, unlike many other types of resonators, it produces a very pure tone, with most of the vibrational energy at the fundamental frequency. The reason for this is that the frequency of the first overtone is about = = ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fundamental Frequency
The fundamental frequency, often referred to simply as the ''fundamental'', is defined as the lowest frequency of a periodic waveform. In music, the fundamental is the musical pitch of a note that is perceived as the lowest partial present. In terms of a superposition of sinusoids, the fundamental frequency is the lowest frequency sinusoidal in the sum of harmonically related frequencies, or the frequency of the difference between adjacent frequencies. In some contexts, the fundamental is usually abbreviated as 0, indicating the lowest frequency counting from zero. In other contexts, it is more common to abbreviate it as 1, the first harmonic. (The second harmonic is then 2 = 2⋅1, etc. In this context, the zeroth harmonic would be 0 Hz.) According to Benward's and Saker's ''Music: In Theory and Practice'': Explanation All sinusoidal and many non-sinusoidal waveforms repeat exactly over time – they are periodic. The period of a waveform is the smallest value of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase (waves)
In physics and mathematics, the phase of a periodic function F of some real variable t (such as time) is an angle-like quantity representing the fraction of the cycle covered up to t. It is denoted \phi(t) and expressed in such a scale that it varies by one full turn as the variable t goes through each period (and F(t) goes through each complete cycle). It may be measured in any angular unit such as degrees or radians, thus increasing by 360° or 2\pi as the variable t completes a full period. This convention is especially appropriate for a sinusoidal function, since its value at any argument t then can be expressed as \phi(t), the sine of the phase, multiplied by some factor (the amplitude of the sinusoid). (The cosine may be used instead of sine, depending on where one considers each period to start.) Usually, whole turns are ignored when expressing the phase; so that \phi(t) is also a periodic function, with the same period as F, that repeatedly scans the same range of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impedance Mismatch
In electronics, impedance matching is the practice of designing or adjusting the input impedance or output impedance of an electrical device for a desired value. Often, the desired value is selected to maximize power transfer or minimize signal reflection. For example, impedance matching typically is used to improve power transfer from a radio transmitter via the interconnecting transmission line to the antenna. Signals on a transmission line will be transmitted without reflections if the transmission line is terminated with a matching impedance. Techniques of impedance matching include transformers, adjustable networks of lumped resistance, capacitance and inductance, or properly proportioned transmission lines. Practical impedance-matching devices will generally provide best results over a specified frequency band. The concept of impedance matching is widespread in electrical engineering, but is relevant in other applications in which a form of energy, not necessarily e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Ear
The middle ear is the portion of the ear medial to the eardrum, and distal to the oval window of the cochlea (of the inner ear). The mammalian middle ear contains three ossicles, which transfer the vibrations of the eardrum into waves in the fluid and membranes of the inner ear. The hollow space of the middle ear is also known as the tympanic cavity and is surrounded by the tympanic part of the temporal bone. The auditory tube (also known as the Eustachian tube or the pharyngotympanic tube) joins the tympanic cavity with the nasal cavity (nasopharynx), allowing pressure to equalize between the middle ear and throat. The primary function of the middle ear is to efficiently transfer acoustic energy from compression waves in air to fluid–membrane waves within the cochlea. Structure Ossicles The middle ear contains three tiny bones known as the ossicles: '' malleus'', '' incus'', and ''stapes''. The ossicles were given their Latin names for their distinctive shapes; they ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rinne Test
Rinne may refer to: People *Aleksi Rinne (1899–1974), Finnish smallholder and politician *Antti Rinne (b. 1962), Finnish politician *Esa Rinne (b. 1943), Finnish athlete *Fanny Rinne (b. 1980), field hockey midfielder from Germany *Fred Rinne (b. 1955), American visual and performance artist *Friedrich Rinne (1863–1933), German mineralogist, crystallographer and petrographer *Heinrich Adolf Rinne, German otologist *Jacob Rinne (b. 1993), Danish footballer * John Rinne (1923–2010), Orthodox Archbishop of Karelia and All Finland *Joel Rinne (1897–1981), Finnish actor *Jorma Rinne (1936–2003), Finnish discus thrower *Jouni Rinne (b. 1956), retired Finnish ice hockey player *Kris Rinne, technology person and retired Senior VP of network technology at AT&T Labs *Paul Rinne (b. 1889–1946), Estonian chess player *Pekka Rinne (b. 1982), Finnish ice hockey goaltender *Rasmus Rinne (b. 1990), Finnish ice hockey goaltender *Rinne Yoshida, Japanese idol singer *Tapani Rinne (b. 1962) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weber Test
Weber (, or ; German: ) is a surname of German origin, derived from the noun meaning " weaver". In some cases, following migration to English-speaking countries, it has been anglicised to the English surname 'Webber' or even 'Weaver'. Notable people with the surname include: Disambiguation of common given names with this surname * Arthur Weber (other), several people * Ben Weber (other), several people * Bruce Weber (other), several people * Bruno Weber (other), several people * Carl Weber (other), several people * Charlie Weber (other), several people * Charles Weber (other), several people * Christiane Weber (other), several people * David Weber (other), several people * Ernst Weber (other), several people * Friedrich Weber (other), several people * Georg Weber (other), several people * George Weber (other), several people * Gerard Weber (disambiguatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Conduction
Bone conduction is the conduction of sound to the inner ear primarily through the bones of the skull, allowing the hearer to perceive audio content without blocking the ear canal. Bone conduction transmission occurs constantly as sound waves vibrate bone, specifically the bones in the skull, although it is hard for the average individual to distinguish sound being conveyed through the bone as opposed to the sound being conveyed through the air via the ear canal. Intentional transmission of sound through bone can be used with individuals with normal hearing — as with bone-conduction headphones — or as a treatment option for certain types of hearing impairment. Bone generally conveys lower-frequency sounds better than higher frequency sounds. Overview Bone conduction is one reason why a person's voice sounds different to them when it is recorded and played back. Because the skull conducts lower frequencies better than air, people perceive their own voices to be lower a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle Velocity
Particle velocity is the velocity of a particle (real or imagined) in a medium as it transmits a wave. The SI unit of particle velocity is the metre per second (m/s). In many cases this is a longitudinal wave of pressure as with sound, but it can also be a transverse wave as with the vibration of a taut string. When applied to a sound wave through a medium of a fluid like air, particle velocity would be the physical speed of a parcel of fluid as it moves back and forth in the direction the sound wave is travelling as it passes. Particle velocity should not be confused with the speed of the wave as it passes through the medium, i.e. in the case of a sound wave, particle velocity is not the same as the speed of sound. The wave moves relatively fast, while the particles oscillate around their original position with a relatively small particle velocity. Particle velocity should also not be confused with the velocity of individual molecules, which depends mostly on the temperature an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acoustic Impedance
Acoustic impedance and specific acoustic impedance are measures of the opposition that a system presents to the acoustic flow resulting from an acoustic pressure applied to the system. The SI unit of acoustic impedance is the pascal-second per cubic metre (), or in the MKS system the rayl per square metre (), while that of specific acoustic impedance is the pascal-second per metre (), or in the MKS system the rayl. There is a close analogy with electrical impedance, which measures the opposition that a system presents to the electric current resulting from a voltage applied to the system. Mathematical definitions Acoustic impedance For a linear time-invariant system, the relationship between the acoustic pressure applied to the system and the resulting acoustic volume flow rate through a surface perpendicular to the direction of that pressure at its point of application is given by: : p(t) = * Qt), or equivalently by : Q(t) = * pt), where * ''p'' is the acoustic pressure; * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Pressure
Sound pressure or acoustic pressure is the local pressure deviation from the ambient (average or equilibrium) atmospheric pressure, caused by a sound wave. In air, sound pressure can be measured using a microphone, and in water with a hydrophone. The SI unit of sound pressure is the pascal (Pa). Mathematical definition A sound wave in a transmission medium causes a deviation (sound pressure, a ''dynamic'' pressure) in the local ambient pressure, a ''static'' pressure. Sound pressure, denoted ''p'', is defined by p_\text = p_\text + p, where * ''p''total is the total pressure, * ''p''stat is the static pressure. Sound measurements Sound intensity In a sound wave, the complementary variable to sound pressure is the particle velocity. Together, they determine the sound intensity of the wave. ''Sound intensity'', denoted I and measured in W· m−2 in SI units, is defined by \mathbf I = p \mathbf v, where * ''p'' is the sound pressure, * v is the particle velocity. Acoustic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Board (music)
A sound board, or soundboard, is the surface of a string instrument that the strings vibrate against, usually via some sort of bridge. Pianos, guitars, banjos, and many other stringed instruments incorporate soundboards. The resonant properties of the sound board and the interior of the instrument greatly increase the loudness of the vibrating strings. "The soundboard is probably the most important element of a guitar in terms of its influence on the quality of the instrument's tone ."Sloane, Irving (1989). ''Classic Guitar Construction'', p.20. Bold Strummer. . "The sound board is the most important element in the guitar." The sound board operates by the principle of forced vibration. The string gently vibrates the board, and despite their differences in size and composition, makes the board vibrate at exactly the same frequency. This produces the same sound as the string alone, differing only in timbre. The string would produce the same amount of energy without the board p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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