With my grade 11 Physics class we are currently studying sound, and we have been using a variety of tools. Here are some of the great free tools that we have found useful:
The title of this software pretty much says it all. It is a compact, easy to use and fairly comprehensive piece of software for recording and editing audio. Perhaps not as well known in educational circles as Audacity, but I find it slightly more intuitive to use. By capturing the full audio signal, the user can see the entire envelope of sound, or zoom in to see the actual waveform. I also use it to record voiceovers for videos or presentations. Could be used for podcasts too. The most recent version I downloaded installed a browser toolbar, but this is easily disabled if unwanted.
Developed by Alfredo Accattatis for academic purposes, and just for the love of it, VA is an oscilloscope and spectrum analyzer that uses nothing more than the sound card on your computer. It shows a live waveform on the oscilloscope, and a live frequency spectrum on the analyzer. It even has a “3d” function so you can see how the frequency changes with time. It can record short snapshots of both the waveform and spectrum for detailed analysis. A very powerful tool.
Here’s a video showing how VA is used:
Raven is produced by the Cornell Lab of Ornithology Bioacoustics Research Program. It is designed to record, play back, visualize and analyze sounds – whether musical notes, complex bird calls or whale songs. The Lite version is free for hobbyists and educators, though it must be “purchased” through the online store to receive an activation license. This software combines many of the features of both Free Audio Editor and Visual Analyzer, in that it records and displays the amplitude trace (waveform/oscilloscope) as well as a frequency spectrogram. This spectrogram is actually a 3-d graph, showing frequency over time, with intensity or colour representing the amplitude. This makes it more complicated for novices to interpret, but shows changes in frequency in a very visual way. It also aligns the frequency response to the waveform, so the two can be compared together.
Since each of these fills a slightly different niche, it is not an either/or thing – I use each of these differently, and I do use all of them. And since they are free, the price is definitely right!