Question: "How does the level meter work?" AB-Joel: "The Level Meter shows how close you are to earning your next level! As you earn points, the Meter fills up, and when it gets to the top, your level will increase. To see how many points you need to earn still, just put your mouse over the Level Meter for a second, and a message should pop up telling you how many points you need." # http://www.answerbag.com/q_view/97075/162587 Instead of filling up to represent the percentage of points you need to reach the next level it works on a sort-of curved graph. In other words, to start with as you gain points your level meter grows very fast, and near the end your level meter grows very slowly. The level meter can only go down if the staff reduce the number of points you have (users can't reduce your total points by down-rating your questions/answers). ----- Graphics wise, it works by working out your points and dynamically drawing rectangle. The bag-image is placed over the top. The centre of the bag is transparent so as the rectangle changes size and colour it looks like the bag is filling up. Or are you asking for specifics as to how it was programmed? If so, I don't know the answer.

A sound level meter is used to measure sound levels, usually in terms of subjective loudness. This involves the use of a weighting filter, usually to the A-weighting standard. The use of A-weighting is historical, and not really justifiable on the basis of current understanding of equal-loudness contours and the fact that these have been shown not to apply for random noise. The use of an rms rectifier, also standard, is also hard to justify. Sound level meters are commonly used in noise pollution studies for the assessment of roadway noise, industrial noise, and aircraft noise. Strictly speaking the A-weighting was only recommended for quiet sounds in the region of 40 dB SPL but today it is used at all levels, and the other weightings are little used, except for D-weighting which is used specifically for Aircraft noise at very high levels. Sound exposure meters use the same principles, and A-weighting, to measure total exposure to noise over a period of time. The result is indicated in terms of LAeqT, which means the equivalent level (A weighted) over a time period T (often 8 hours). The equivalent level is derived by storing a large number of sound pressure values in pascals and then calculating the mean square before converting to dB SPL. High levels thus count more in the final figure. Exposure meters are usually used to assess high level industrial noise, in terms of potential for hearing damage, though they use the A-weighting curve which was derived from equal-loudness contours at very low level(40 dB SPL). The ITU-R 468 noise weighting curve was designed specifically for noise measurement, along with a quasi-peak detector, and though used mostly for professional audio equipment measurements, would actually produce more meaningful results if incorporated into sound level meters for low level noise measurement.

I was wondering that a couple of days ago. This is the source code for the meter on my profile, currently. <td style="width: 60px;"> <div id="level_meter_container" style="cursor: pointer;" onclick="window.location='/q_view/97075';"> <div id="level_meter" style="height: 9px; background: rgb(100%,12%,0%);"> </div> <div id="level_meter_image" title="196 points until level 20"></div> </div> </td> The first line is the width of the level meter. The second line says what happens when you click on it. The third line dictates the height and the color of the colored part. The fourth line tells how many points you have to go to reach the next level. I don't know how it was programmed to track points.