1 / 12

Sound Filters and Spectral Analysis

Learn about various types of sound filters such as High-Pass, Low-Pass, Band-Pass, and Band Reject, with details on cutoff frequency, rolloff, and their effects. Explore the concept of gating and its impact on spectral splatter, alongside information on distortion and its types.

tmahlum
Télécharger la présentation

Sound Filters and Spectral Analysis

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 5 Sound Analysis

  2. Filters Shape Spectra • Attenuating (reducing) amplitudes in certain frequency ranges • Come in different types: • High-Pass • Low-Pass • Band-Pass • Band Reject

  3. All Filters have definable: • Cutoff Frequency: Where attenuation reaches 3 dB • Rolloff: Rate (in dB/Octave) at which attenuation increases

  4. Low and High Pass Filters

  5. Band Pass and Reject Filters

  6. Example of a Filter’s Effect

  7. Gating: Turning Sounds On and Off • A tone on continuously theoretically has energy at only one frequency • Turning a tone on and off will distort it and produce energy at other frequencies

  8. Gating Terms: • Onset--When amplitude begins to grow from zero. • Rise Time -- Time taken for amplitude to go from zero to largest value. • Offset--When peak amplitude begins to decrease from largest value. • Fall Time -- Time taken for peak amplitude to go from largest value to zero.

  9. Gating Effects--Spectral Splatter • The Shorter the Rise/Fall Times, the greater the spread of energy to other frequencies. • The Longer the Rise/Fall Times, the lesser the spread of energy. • Overall (or Effective) Duration also controls spectral splatter

  10. Distortion: • Broad definition = any alteration of a sound • Specific def. = Addition of energy at frequencies not in the original sound • Devices that produce distortion are said to be “nonlinear”

  11. Examples of Distortion: • Harmonic Distortion = adding energy at multiples of input--often seen when peak-clipping occurs • Intermodulation Distortion = production of energy at frequencies which are sums and/or differences of the input frequencies.

  12. Nonlinearities • Input + additional sinusoids = nonlinear output • Additional tones are combinations tones • Summation tones (f1+f2, 2f1+f2, f1+2f2…) • Difference tones (f1-f2, 2f1-f2, 2f2-f1…) • Input + change of time-domain waveform = distorted (nonlinear) output

More Related