Getting ready to learn about decibels:
a tutorial on logarithms
We are about to learn about decibels, or a method of measuring the perceived loudness of sounds, including speech sounds. Before we do this, however, we need a clear understanding of logarithms. Many liberal arts students have been away from math and the sciences for some years, and panic on hearing the name of any mathematical operation. In fact, less-than-top grades in high school math may be one of the main reasons you're studying a course in phonetics rather than in linear algebra or advanced calculus!
Well, you can relax. Mark Huckvale of the University College London has designed a very clear and easy online tutorial for learning or reviewing logarithms. You may want to break it up and complete it in more than one sitting; and it would be a good idea to work through the whole tutorial at least two or three times to make sure you understand the material thoroughly. Here is the URL:
If you have a good scientific calculator, get that out to check the calculations and do your own. If you don't have a calculator, then open the one included in your computer's operating system, and choose 'engineering' mode. The functions you will need most, beyond addition, subtraction, multiplication and division, are logarithm, antilogarithm, square, and square root.
When you have finished the tutorial, you will be ready for the PowerPoint slide show on decibels. We will show it and discuss it in class, but there is a lot of relatively heavy material in it, so it is provided for you here to review at your leisure.
Ready now? Then on to...