Sound level, definition

Sound is indicated as sound level Lp (sound pressure level). The definition Equation (6-1) applies in this case ... 

The reference sound pressure used here is the sound pressure of a sinus sound with a frequency of 1 kHz the human ear is barely able to perceive it (hearing threshold). The sound energy penetrating through the area unit per unit of time is described as sound intensity, sound density, or sound level J. The value of sound intensity at the hearing threshold is approximately /(,= 10 W/m. This value permits a definition of the sound intensity level with the help of Equation (6-2) ... 

The term definitive method is applied to an analytical or measurement method that has a valid and well described theoretical foundation, is based on sound theoretical principles ( first principles ), and has been experimentally demonstrated to have negligible systematic errors and a high level of precision. While a technique may be conceptually definitive, a complete method based on such a technique must be properly applied and must be demonstrated to deserve such a status for each individual application. A definitive method is one in which all major significant parameters have been related by a direct chain of evidence to the base or derived SI units. The property in question is either directly measured in terms of base units of... 

These particular points relate to each individual trial, but equally there will be similar considerations needed at the level of the development plan. In order for the overall, ordered programme of clinical trials to be scientifically sound there needs to be a substantial amount of commonality across the trials in terms of endpoints, definitions of analysis sets, recording of covariates and so on. This will facilitate the use of integrated summaries and meta-analysis for the evaluation and presentation of the complete programme or distinct parts of that programme, and outside of that, will allow a consistency of approach to the evaluation of the different trials. 

Scaling experiments using steady-state signals have shown that the loudness of a sound is a non-linear function of the intensity. Extensive measurements on the relationship between intensity and loudness have led to the definition of the Sone. A steady-state sinusoid of 1 kHz at a level of 40 dB SPL is defined to have a loudness of one Sone. The loudness of other sounds can be estimated in psychoacoustic experiments. In a first approximation towards calculating the internal representation one would map the physical representation in dB/Bark onto a representation in Sone/Bark ... 

Through irmovative pollution prevention, effective facility management, and sound acquisition and procurement practices, contractors shall assist DOE in reducing its reported releases and off-site transfers of toxic chemicals subject to annual toxic release reporting under EPCRA (see definition) (see section 4.6 of this chapter) for treatment and disposal by 10 percent annually, or by 40 percent overall by December 31, 2006 from year 2000 levels. 

Noises are considered continuous if the interval between occurrences of the maximum noise level is 1 second or less. Noises not meeting this definition are considered impact or impulse noises. Exposure to impact or impulse noises (loud momentary explosions of sound) must not exceed 140 dBA. Examples of impact or impulse noises may include the noise from a powder-actuated nail gun, the noise from a punch press, or the noise from drop hammers. 

A sound and workable definition of acceptable risk must encompass hazards, risks, probability, severity, and economic considerations. Also, in the following definition, it is made clear that a risk level as low as reasonably practicable must also be tolerable ... 

For the practice of safety to be recognized as a profession, it must have a sound theoretical and practical base that, if applied, will be effective in hazard avoidance, elimination, or control and achieving acceptable risk levels. This author believes that there is a generic base for the work of safety professionals that must be understood and applied if they are to be effective. But, safety professionals have not yet agreed on those fundamentals or on the definitions of related terms. As Grimaldi and Simonds (1989) wrote in Safety Management. 

The basic definition of leadership is influence. It sounds simple but is very complex. It really includes the process and relationship that exists between leader and follower. John Maxwell has very brilliantly captured the relationship of leader and follower in his model of the levels of leadership. In his model, there are live levels of leadership, as shown in Figure 34.1, and the levels are determined by the reason that the constituents allow the leader to influence them. 

The argumentation so far can be encapsulated as a particular perspective on safety that 1 will call Safety-1, for reasons that soon will become obvious. Safety-1 defines safety as a condition where the number of adverse outcomes (accidents/incidents/ near misses) is as low as possible. (While as low as possible sounds nice, it really means as low as affordable, where what is affordable is determined by considerations of cost, of ethics, of public opinion, etc. As low as possible is therefore not as nice or as simple as it sounds, but that is another story.) It follows from this definition that the purpose of safety management is to achieve and maintain that state, i.e., to reduce the number of adverse events to an acceptable level. Examples of Safety-1 are easy to find. A common dictionary definition is that safety is the condition of being safe from undergoing or causing hurt, injury, or loss, where safe somewhat redundantly is defined as free... 

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