This is a quietness meter I designed for teachers to help their classes maintain an appropriate volume level. Students can get an accurate gauge of what an “inside voice” really sounds like, and can get real time feedback on their volume. "Quietness" is a real time measure of how quiet the class is being. I thought that in since we are generally trying to encourage quietness, it made sense to have a quietness score rather than a loudness score. The quietness score is actually out of 100, but the range is -90 to 10. That way, only quietness in the top ten percent is perceived as positive. The "goal" is the minimum quietness you want your class to maintain. I usually leave it at 5, (ie. 95% of total quietness) but you can adjust it by pressing the up and down arrow keys, or by pressing the space bar and typing in a number manually. When the goal is being met, "Good!" is displayed in big letters. When it is not, "Too Loud!" is displayed. The "score" is simply the percentage of time since the last reset that the class has met the goal. Clicking reset will reset the value of Score. Clicking start will start measuring the quietness, clicking stop will pause the measure. Note that if you click reset while the program is stopped the reset will not seem to take effect until you start the program again. Of course, microphone placement and choice has a big impact on what actual scores you get. I tried three microphones, and nearly all of them were only sensitive to sounds within a few feet. Only my Macbook's built in mic seems to pick up sounds from the entire room. Also, I had to adjust the input gain setting on my Mac to get things where I wanted them. Of course, proximity is also a factor, and the program will be more sensitive to students closer to the mic, but the kids don't need to know that.
