Digital Filters Applet

People who are involved in audio processing, students or just users who are passionate about the audio field, could be looking for a way of interactively learning about the effect of digital filters on the audio signal. Of course, there are endless resources that can provide insight in such matters, but Digital Filters Applet tries to provide a different, accessible approach. It will enable people to actively alter the different filters and preview in realtime, their effect on the waveform of the audio signal.

The application presents users with a minimalist yet highly configurable interface that provides several tools for adjusting and previewing the audio waveform. Featuring multiple views for the different parameters that control the characteristics of the audio signal waveform, the utility will allow one to define the preferred display type.

People will be able to use a side-panel that offers multiple predefined inputs, filters and sampling rates that can be easily selected from accessible dropdown menus. They will be able to alter parameters such as the cuttoff frequency, order or shift frequency. However, all the displayed audio graphs will feature the same color and they would have been easier to to differentiate with different styles.

The application will offer users the choice of using background noise as audio signal input or predefined recordings with different characteristics: sine wave, sawtooth wave, sweep, etc. By using the provided menu, one can toggle several parameters that can be displayed on the different audio signal graphs: frequency / phase response, spectrum, waveform, impulse / step response, Ferris plot, etc.

All the applied filters’ effects on the audio signal can be previewed in realtime and the waveform’s characteristics will shift accordingly, allowing one to better understand the involved changes. A special muting button is provided and people can easily silence the application, but by using it, the audio signal preview will terminate abruptly.

Considering its straightforward interface and ease-of-use, this application could be a great choice for those who prefer to learn about the effects of digital audio filters, in an interactive way. It will allow them access to a predefined library of sounds with different waveforms, onto which they will be able to apply various filters and preview their effect on the audio signal waveform.