Sound Spectrum Viewer Notes
Notes:
Teaching Ideas and Suggestions:
The Interactive displays a spectrogram of the sound that it captures. A spectrogram is a real-time, visual representation of the sound frequency and intensity over the course of time. The frequency is plotted along the vertical axis and the time is plotted along the horizontal axis. The most currently-recorded sounds are displayed on the right side of the graph. In this sense, "now" is on the far right. The amplitude or intensity of the sound is represented by the color. Spectrograms are sometimes referred to as sonographs or voiceprints.
The Interactive will also display the Fast Fourier Transform of the collected sound. The FFT display plots the frequency along the horizontal axis and the amplitude along the vertical axis. The FFT is a dynamic display that constantly changes with time to reflect the latest sound gathered from the device microphone. It is very useful for analyzing the sound produced by a musical instrument. The harmonic frequencies will rise above the noise as frequency peaks. For best results, play the instrument, collect the sound and be ready to tap on the Pause button was a relatively good FFT display appears. The frequency of the most dominant peak will be displayed on the screen.
Our original intent was to provide this tool as an accompaniment to the Data Transmission Interactive. Our thought was that students could use Sound Spectrum Viewer to analyze the spectrum of the sound transmitted by Data Transmission. An interesting study involves analyzing the spectrogram of a message transmitted using the Single Frequency mode and comparing it to the same message being transmitted using the 16-bit mode.
Since the original release, we have added the FFT display. The FFT display opens up a variety of new possibilities for classrooms using this tool. While this was our reason for creating the Interactive, we are sure that users will find other uses of this tool. It is a supurb tool for supporting student project work. As a tool, it has wide application.
Related Resources:
- Communicating with Waves
This NGSS-inspired task includes three parts that focus on the sending, encoding, and storage of information by means of electromagnetic waves.
- Digitizing Data
This NGSS-inspired task addresses the manner in which data (such as graphic images) can be digitized and the issues associated with the transmitting, receiving, and storage of digital data.
Visit: Sound Spectrum Viewer Interactive
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