There are currently four illusions to explore in the SoundGarden. Select one of the following for more information:

Scale Illusion – Do you hear a smooth or jagged melody?

Pitch Streaming – What happens when the pattern speeds up?

Octave Illusion – In which ear do you hear the high or low tone?

Shepard's Tones – Why do these tones always go up in pitch?

Meathead, you've got to set this up! Also, you saved a midi file with the volume changes on it. Add that as an extracurricular activity.

Win95

There is free spectrum analyzer software for Windows95 called Spectrogram. It is available here.

Spectrogram is easy to use and provides excellent visualizations of sound files. Note: it works only with .wav files, the Microsoft sound format. You may need your system administrator to set this up for you. Have them refer to this page for the proper links.

Since this file is compressed you will need a shareware tool called Winzip95. If your WWW browser has been configured to use Winzip95, this processing will be performed automatically. Otherwise, the files must be loaded to your hard drive and processed outside of your WWW browser. Winzip95 is available here.

MAC

There is a low cost program called Sound Waves that is available with a money back guarantee. More information is available here.

TIP: the links on this page take you places on the Internet that don't have navigational buttons back to this page. If you use them, please use the BACK button on the top left of your browser to return to this page and continue.

These links may provide you with other ideas for preparing a lesson that uses the Shepard's Tone Illusion.

More Shepard's Tones #1 – excellent examples of Shepard's Tones from Norma Welch's site.

More Shepard's Tones #2 – a clever imagemap that lets you play and hear individual tones within an octave span.

More Shepard Tones #3 – nice charts and sound examples of the tones.

More Shepard's Tones #4 – also called 'pitch circularity,' from the Acoustical Society's Auditory demonstration CD.

Risset's Endless Glissando (aka More Shepard's Tones #5) – this resource has quicktime movies and sound examples that show how the various tones get louder and softer, while changing their pitch.