![• Of course, in our computer
we use digital oscilloscopes.
For example, this one, a free
oscilloscope for Max for
Live:
Jo.Oscilloscope, by Jonas Obermüller
• Or this one, also free:
S(M)exoscope, by SmartElectronix
[Click in the images for downloads]](https://image.slidesharecdn.com/visualizingsoundsvideo-160417182753/85/Visualizing-sound-6-320.jpg)
![• Here are a couple of examples of Spectrum
Analyzers:
SPAN, by Voxengo
[Click in the images for free
downloads]
FreqAnalyst, by Blue Cat
Audio.](https://image.slidesharecdn.com/visualizingsoundsvideo-160417182753/85/Visualizing-sound-14-320.jpg)
Visualizing sound
- 1. VISUALIZING SOUND C O U R S E R A P R E S E N T A T I O N
- 2. PRESENTING THE PRESENTATION • Hi! I’m Rodrigo De la Prida from Santiago, Chile. The present lesson is for week 1 of Introduction To Music Production, at Coursera.org, and is about the different ways of visualizing sound. I hope you enjoy!
- 3. • A visual representation of sound helps us understand what we hear. We can see parameters such as frequency, amplitude and timbre, and how they are affected by processing sound.
- 4. THE WAYS • We will discuss the main and most used ways for the visual representation of sound, and the digital electronic devices responsible for show it to us. These devices are the Ocilloscope, the Spectrum Analyzer, and the Sonogram. Let’s see them!
- 5. THE OSCILLOSCOPE • This device presents a very detailed representation of the sound, in real time, and in 2D. • The values of the audio signal are displayed as coordinates through a screen, what we know as oscillogram. The X axis (horizontal) represents time, and the Y axis (vertical) represents amplitude (dB, dBFS). Analog Oscilloscope
- 6. • Of course, in our computer we use digital oscilloscopes. For example, this one, a free oscilloscope for Max for Live: Jo.Oscilloscope, by Jonas Obermüller • Or this one, also free: S(M)exoscope, by SmartElectronix [Click in the images for downloads]
- 7. • In the oscillogram we can view sine, triangular, square, and saw tooth waveforms, and appreciate how the shape is different between them. Sine waveform Triangular waveform Saw Tooth waveform Square waveform
- 8. • The main limitation with the oscilloscope is related with the frequency analysis. We really can’t see it clearly, because the view is so microscopic. Generally we can only see a very small part of a second, or a full second, and counting the repetitions of a wave cycle in every second seems pretty impractical. • So, in order to see and analyze the frequency of the signal, we really need another device, called Spectrum Analyzer.
- 9. THE SPECTRUM ANALYZER • With the Spectrum Analyzer is possibly to see several spectral components of the audio signal, like bandwith, dominant frequency, and harmonics. • The frequency of the signal, measured by Hertz, is showed through the horizontal axis, or X, and the amplitud in the vertical axis, or Y. Analog Spectrum Analizer
- 10. • With the Spectrum Analyzer we can appreciate the differences in the harmonic content, between the four audio waveforms: sine, square, triangular, and saw tooth. Sine waveform • Basically we see the fundamental frequency and the absence of harmonics, which defines sine waves. Look at the bottom left corner. In this orange square the Spectrum, from Ableton Live, shows the frequency (262 Hz), note pitch and octave (C3), and the amplitude (-13.7 dB).
- 11. Square waveform • In this waveform we can see several harmonics added to the fundamental frequency. Specifically, odd harmonics. Non-sinusoidal waveforms Triangular waveform • Also with odd harmonics, but the higher ones roll-off much faster than in a square wave.
- 12. Saw Tooth waveform • This waveform includes the odd and pair harmonics.
- 13. • The Spectrum Analyzer is widly use for the frequencies analysis in filters. It’s very common see them in the displays of the equalizers. EQ Eigth, from Ableton Live. Pro-Q2, from fabfilter.
- 14. • Here are a couple of examples of Spectrum Analyzers: SPAN, by Voxengo [Click in the images for free downloads] FreqAnalyst, by Blue Cat Audio.
- 15. THE SONOGRAM • With this device we can see the audio signal evolution in time. • Now, the frequency of the signal is showed through the vetical axis, or Y, and the time is showed in the horizontal axis, or X. Also it has another axis, the Z, and it represents the amplitude with colors. Sonogram View
- 16. • The color range goes from the blue, for the minimum amplitude, to the red, the maximum. • We can see that in this sonogram of an American Goldfinch:
- 17. • Here are two examples of software that offers the sonogram view: Lab TS, by IRCAM. The Snail, by IRCAM.
- 18. This presentation was made for the Coursera.org course “Introduction to Music Production”. Santiago, Chile, February - 2016 Press the button!