Welcome to the Sonic Website
Live Visualizer
Navigating This Site
There are a few important things to know about using, listening to, and navigating through this site:
1. Sidebar navigation. To reach a different chapter or section, use the sidebar menu on the left (or tap the menu button on mobile). One can jump directly to any chapter from there. The sidebar is the main way to move through the site.
2. Key terms. Text that appears in red with a dashed underline indicates a key term being introduced or defined for the first time. Click or tap any such term to jump to its entry in the glossary, which links back to the chapter where the term is first explained.
If red text indicates a figure number, clicking or tapping it jumps to that figure’s location in the chapter. Use the browser’s back button to return to where the figure was first mentioned.
3. Inline sound examples. Throughout the text are distinctive audio links like . Clicking or tapping one of these plays a sound example directly in the browser. Navigating to a new sound example or clicking or tapping the next/previous button will stop the current sound.
4. Numbering of figures and chapters. The number before a decimal point identifies the chapter; the number after it is the figure within that chapter. For instance, figure 9.3 refers to Chapter 9, Figure 3.
5. Volume control. Many pages include a volume slider that adjusts the relative playback level of sound examples. Note that the operating system and browser volume settings also affect the final level heard.
Some Important Notes About Sound Examples
We’ve written the text so that at strategic moments in the exposition one sees an in a distinctive style. Sound is generated in the browser, so nothing needs installing: plays the example over speakers or headphones — worth trying now. If nothing is heard, see the troubleshooting section below.
This site, while visually rich and interactive, is best thought of as a talking book with figures and sound examples — the interface exists to support the content, not the other way around. Listening several times to each example is encouraged—sometimes at different sound levels, sometimes through loudspeakers, and sometimes through headphones. When reference is made to a previous section, comparing the earlier sounds as well as the earlier text is encouraged. Nothing compares to careful, repeated listening of sound examples to learn about a new audio concept. In some cases, the audio examples are very obvious, and in other cases the examples are subtle. While a low-grade audio system will mask some of the effects, a wide variety of standard consumer audio setups should work just fine for hearing all of the examples.
On a few of the examples, especially in Chapter 9, it is best enjoyed with a pair of good quality headphones. Most computers and mobile devices have a headphone jack or supports Bluetooth headphones.
Troubleshooting Sound Playback Problems
This site uses the Web Audio API, and is developed and tested against current Chrome, Firefox, Safari, and Edge. One known limit: on iPhone, Safari in an ordinary browser tab cuts sounds short after roughly 0.4 s — adding the site to the Home Screen removes that, as does using Chrome or Firefox there. iPad Safari is unaffected. If trouble is experienced hearing sound:
- Check the browser. Make sure to use an up-to-date version of Chrome, Firefox, Safari, or Edge. Older browsers may not support Web Audio.
- Interact with the page first. Modern browsers require a user interaction (such as a click) before audio can play. Click or tap a sound link or the play button on any demo to enable audio.
- Check system volume. Ensure the operating system volume is turned up and not muted. On mobile devices, check that the ringer/media volume is not silenced.
- Check browser permissions. Some browsers or extensions may block audio autoplay. Look for a blocked-audio icon in the address bar and allow audio for this site.
- Test other audio. Try playing a video or other audio on a different website. If that also fails, the issue lies with the system audio settings or hardware connections, not this site.
- Check hardware connections. If using external speakers or headphones, verify they are plugged in (or paired via Bluetooth) and powered on.
For a structured walk-through of the playback chain — channel assignment, phase, frequency response, dynamic range — visit the Audio Self-Test page (a pseudo-chapter at the end of the main contents). It bundles the chapter 8 tests into one place with step-by-step procedure cards.
Interactive demos & figures, by chapter
For straight chapter navigation, use the sidebar (or the hamburger menu on mobile). The index below deep-links into specific interactive demos and animated figures within each chapter.
This site’s interactive demos and animated figures are grouped here by chapter, so any one can be reached directly. “Fig n.m” entries are the original numbered figures from the book; bracketed labels are demos added for this edition. See also the running modernization log on What’s New.
Chapter 1 — Communication, Frequency & Pitch
- Fig 1.10 — Molecule-wave visualizer (animated longitudinal pressure wave)
- Fig 1.13 — Tone generator (waveform + frequency + gain, with live spectrum)
- Fig 1.14 — Live keyboard (two-octave piano with scrolling spectrogram)
- Fig 1.16 — Beating demo (two close-frequency sines)
Chapter 2 — Intensity & Loudness
- Fig 2.1 — RMS, peak & peak-to-peak
- Fig 2.3 — Equal-loudness contours (draggable test tone + age/presbycusis slider)
- Fig 2.5 — Hard-clipping a periodic source
Chapter 3 — Spectra, Modulation & Phase
- Fig 3.2 — 10-band graphic equaliser
- Fig 3.3 — Guitar-string harmonic samples
- Fig 3.4 — Harmonics builder (eight-partial additive synthesis with presets)
- Fig 3.5 — Fourier Sandbox (16-harmonic + DC, draw → DFT, polar/rectangular, waveform operators, narrowcasting, 1/nk overlays, hover-highlight)
- Fig 3.8 — Additive harmonic envelope
- Fig 3.9 — Sawtooth partial sums
- Fig 3.13 — Noise Color Explorer
- Fig 3.14 — ADSR live (with draggable vertices)
- Fig 3.15 — ADSR stereo
- Fig 3.21 — FM modulation
- Fig 3.22 — AM modulation
- Fig 3.27 — Stereo polarity / channel crossing
Chapter 5 — Miking & Recording
Chapter 6 — Digitization & Editing
- Fig 6.3 — Quantiser (1–24-bit re-quantization with optional dither)
- Fig 6.12 — VU meter (vintage-needle ballistics)
- Fig 6.15 — Live clipping
Chapter 7 — Effects & DSP
- Fig 7.8 — 3D spectrogram waterfall
- Fig 7.10 — Digital delay
- Fig 7.15 — Filter (LP / HP / BP / notch)
- Fig 7.17 — Reflection animation (rays bouncing off room walls)
- Fig 7.20 — Reverb (small room / hall / cathedral)
- Fig 7.22 — Compressor
- Fig 7.23 — Pitch-curve glissando
Chapter 9 — 3D Sound & Auralization
- Fig 9.3 — 3D sound spatializer (with continuous head-rotation control)
- Fig 9.4 — Narrowcasting Sandbox (multi-source / multi-sink HRTF, source & sink directivity, mute/solo/deafen/attend per Cohen 2000, camera head-tracking, room reverb presets)
Extras — Shepard tones & auditory illusions
- Shepard Walker (polyphonic press-and-hold keyboard)
- Shepard tone generator