Directional terms

The body of the Bidirectional Algorithm uses bidirectional character types, explicit formatting characters, and bracket pairs to produce a list of resolved levels. This resolution process consists of the following steps:

Directional terms

Supercardioid Shotgun A microphone's directionality or polar pattern indicates how sensitive it is to sounds arriving at different angles about its central axis. The polar patterns illustrated above represent the locus of points that produce the same signal level output in the microphone if a given sound pressure level SPL is generated from that point.

How the physical body of the microphone is oriented relative to the diagrams depends on the microphone design. For large-membrane microphones Directional terms as in the Oktava pictured abovethe upward direction in the polar diagram is usually perpendicular to the microphone body, commonly known as "side fire" or "side address".

Some microphone designs combine several principles in creating the desired polar pattern. Omnidirectional[ edit ] An omnidirectional or nondirectional microphone's response is generally considered to be a perfect sphere in three dimensions.

In the real world, this is not the case. As with directional microphones, the polar pattern for an "omnidirectional" microphone is a function of frequency.

The body of the microphone is not infinitely small and, as Directional terms consequence, it tends to get in its own way with respect to sounds arriving from the rear, causing a slight flattening of the polar response.

This flattening increases as the diameter of the microphone assuming it's cylindrical reaches the wavelength of the frequency in question. Therefore, the smallest diameter microphone gives the best omnidirectional characteristics at high frequencies.

Omnidirectional microphones, unlike cardioids, do not employ resonant cavities as delays, and so can be considered the "purest" microphones in terms of low coloration; they add very little to the original sound. Pressure-sensitive microphones also respond much less to wind noise and plosives than directional velocity sensitive microphones.

An example of a nondirectional microphone is the round black eight ball. The diagram above illustrates a number of these patterns. The microphone faces upwards in each diagram. Professional diagrams show these scales and include multiple plots at different frequencies.

The diagrams given here provide only an overview of typical pattern shapes, and their names. Cardioid, hypercardioid, supercardioid, subcardioid[ edit ] University Sound USA dynamic supercardioid microphone The most common unidirectional microphone is a cardioid microphone, so named because the sensitivity pattern is "heart-shaped", i.

The cardioid family of microphones are commonly used as vocal or speech microphones, since they are good at rejecting sounds from other directions. In three dimensions, the cardioid is shaped like an apple centred around the microphone, which is the "stem" of the apple.

The cardioid response reduces pickup from the side and rear, helping to avoid feedback from the monitors. Since these directional transducer microphones achieve their patterns by sensing pressure gradient, putting them very close to the sound source at distances of a few centimeters results in a bass boost due to the increased gradient.

This is known as the proximity effect. The cardioid is effectively a superposition of an omnidirectional pressure and a figure-8 pressure gradient microphone; [41] for sound waves coming from the back, the negative signal from the figure-8 cancels the positive signal from the omnidirectional element, whereas for sound waves coming from the front, the two add to each other.

By combining the two components in different ratios, any pattern between omni and figure-8 can be achieved, which comprise the first-order cardioid family. A hyper-cardioid microphone is similar to cardioid, but with a slightly larger figure-8 contribution, leading to a tighter area of front sensitivity and a smaller lobe of rear sensitivity.

It is produced by combining the two components in a 3: This ratio maximizes the directivity factor or directivity index. It is produced with about a 5: This ratio maximizes the front-back ratio; the energy ratio between front and rear radiation. It is produced with about 7: Most ribbon microphones are of this pattern.

In principle they do not respond to sound pressure at all, only to the change in pressure between front and back; since sound arriving from the side reaches front and back equally there is no difference in pressure and therefore no sensitivity to sound from that direction.

In more mathematical terms, while omnidirectional microphones are scalar transducers responding to pressure from any direction, bi-directional microphones are vector transducers responding to the gradient along an axis normal to the plane of the diaphragm. This also has the effect of inverting the output polarity for sounds arriving from the back side.

Shotgun and parabolic[ edit ] An Audio-Technica shotgun microphone The interference tube of a shotgun microphone. The capsule is at the base of the tube. A Sony parabolic reflector, without a microphone.

The microphone would face the reflector surface and sound captured by the reflector would bounce towards the microphone. Shotgun microphones are the most highly directional of simple first-order unidirectional types.

At low frequencies they have the classic polar response of a hypercardioid but at medium and higher frequencies an interference tube gives them an increased forward response. This is achieved by a process of cancellation of off-axis waves entering the longitudinal array of slots.

Directional terms

A consequence of this technique is the presence of some rear lobes that vary in level and angle with frequency, and can cause some coloration effects.In many instances, these terms can be example, a posterosuperior view combines the posterior and superior, giving us a view in which we are looking down at the back of the body, like so.

With me so far? No? Okay, let’s do a practice one. Don’t be afraid to refer to the chart before you answer.

Horse Anatomy Diagrams - Directional Terms, Skeleton, and Superficial Muscles

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1 proximal distal lateral medial superior (cranial) inferior (caudal) anterior (ventral) NOT SHOWN posterior (dorsal) Directional Terms Distal-farther from trunk Proximal-closer to trunk Lateral-away from midline Medial-closer to midline Anterior-front side in Posterior-back side in anatomical position anatomical position.

The first microphone that enabled proper voice telephony was the (loose-contact) carbon was independently developed by David Edward Hughes in England and Emile Berliner and Thomas Edison in the US.

Although Edison was awarded the first patent (after a long legal dispute) in mid, Hughes had demonstrated his working device in front of many witnesses some years . The Average Directional Index (ADX) is used to measure the strength or weakness of a trend, not the actual direction.

Directional movement is defined by +DI and -DI. Anatomical position is always the default and all directional terms and body positions are spoken in terms of anatomical position so that medical personnel are in synch.

Anatomy Directional Terms - Anatomy and Physiology Study Notes