Sound loudness

Phonophobia A fear of or intolerance to sounds, loud noises, and even one s own voice. 

So what brought you here I ask Mark, and my voice sounds loud and awkward from having too much behind it. 

Natural evolution has provided animals with logarithmic sensors, and therefore electronic technologists use a log scale to express differences in sound loudness, and also in the corresponding electrical signals. The ear responds to power per eardrum area, and the latter can be kept constant in a given set of experiments. A convenient logarithmic ratio of power differences is the "bel," named after Alexander Graham Bell, the inventor of the telephone (and founder of AT T Corp., the author s employer for many years). 

Sound is measured by its frequency and intensity. Frequency is the pitch (high or low) of a sound. High-frequency sound can be more damaging to your hearing than low-frequency sound. Intensity is the loudness of a sound. Loudness is measured in decibels (dB). 

A positive test can usually be observed as in Figure 6 by a bright flash of flame from the test cup, accompanied by some noise of detonation. Occasionally, a sample detonates without flame or sound loud enough to be heard above the clang of the detonator. In such cases, the test cup and striker must be examined for any burn evidence indicating detonation. In all cases the LOX cleaned test cups and strikers are handled with care, using cleaned stainless steel tongs to protect the surfaces from contamination. After each test the aluminum test cup is discarded, and the striker pin is cleaned prior to reuse. 

Heard loud explosion. Ran to control room and found that the windows had been blown in. Supervisor then sounded plant alarm. Then went to separation module and found it severely damaged and on fire. 

For convenience, the usual measurement of sound is expressed in decibels (dB), and ratings go from threshold of hearing to threshold of pain (135 dB). Figure 34.11 illustrates the common noise criteria, which can be expressed in sound-pressure levels (SPL). The human ear can detect 1 dB but 6 dB represents a doubling of the SPL, although it would need a 10 dB increase to make it sound twice as loud. 

Weighting can be imposed on noise readings, which corresponds to the inverse of the equal-loudness contours. If this weighting is used, all readings that are numerically equal will sound equally loud, regardless of frequency. 

After a few weeks, the new tenant has made a number of observations consistent with the existence of a Thursday garbage collector. Most important, the garbage does disappear every Thursday morning. Second, he receives a bill from the city once a month for municipal services. And there are several supplementary observations that are consistent—often he is awakened at 5 00 a.m. on Thursdays by a loud banging and sounds of a truck. Occasionally the banging is accompanied by gay whistling, sometimes by a dog s bark. 

Findings on the physical exam are often normal in patients with chronic stable angina. However, during episodes of ischemia, patients may present with abnormal heart sounds, such as paradoxical splitting of the second heart sound, a third heart sound, or a loud fourth heart sound. 

Ice is sold in the out-parts of the City in open places Their way of making it is thus... In less than eight Days Working after this Manner, they have Pieces of Ice five or six Foot thick and then they gather the People of that Quarter together, who with loud Shouts of joy, and Fires lighted upon the Edges of the Hole, and with the Sound of Instruments to Animate them, go down into it, and lay these Lumps of Ice one upon the other [1],... 

Her voice is soft and smooth as silk, barely audible at times as a result of chemical exposures. In addition to chemicals she is extremely sensitive to light and sound, including the sound of her own voice. When I asked her to speak a little more loudly to ensure that her voice would be recorded on tape, she responded incredulously with, You mean Tm not shouting Her eyes are beautiful reflecting pools often hidden behind dark glasses, because her eyes turn blood red and burn when exposed to bright light. 

We want to turn up the radio because it s noisy outside, and we want to hear what is broadcast. We therefore turn the volume knob toward loud . At its most basic, the volume control is a variable resistor, across which we pass a current from the battery, acting much like a kettle element. If we turn up the volume control then a larger current is allowed to flow, causing more energy to be produced by the resistor. As a listener, we hear a response because the sound from the speakers becomes louder. The speakers work harder. 

Dennis then sat up in his hammock. I put out the candle, and he sounded his first howl of hyper-carbolation. It was mechanical and loud, like a bull roarer, and it ended with a convulsive spasm that traveled throughout his body and landed him out of his hammock and onto the floor. 

In forming whistling fireworks, the aromatic compounds described above are mixed with oxidisers such as potassium nitrate or potassium perchlorate and pressed into tubes. On combustion, a loud whistling sound is produced, whose pitch is related to the length and diameter of the tube. 

Two basic audible effects are produced by explosive and pyrotechnic devices a loud explosive noise (called a "report" or "salute" in the fireworks industry) and a whistling sound. 

A report is produced by igniting an explosive mixture, usually under confinement in a heavy-walled cardboard tube. Potassium chlorate and potassium perchlorate are the most commonly used oxidizers for report composi s, which are also referred to as "flash and sound" mixtures. hese mixtures produce a flash of light and a loud "bang" upon ignition. Black powder under substantial confinement also produces a report. 

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