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Interpolation accuracy

The Interpolation accuracy value determines the complexity of the interpolation method used during resampling. Interpolation accuracy is most apparent in high frequencies, but the audible difference between the values is subtle and often undetectable without the use of test tones.

A value of 1 is suitable for general-purpose audio.

A value of 2 or 3 is good for high-end audio applications.

A value of 4 results in professional-quality audio, but requires substantial processing.

Apply an anti-alias filter during resample

Selecting this check box applies an anti-aliasing filter during the resampling process. Remember that the maximum frequency that can be represented by a sample rate is one-half of the sampling rate (the Nyquist frequency). Therefore, high frequencies cannot be accurately represented when downsampling. The anti- aliasing filter prevents high frequencies from becoming low-frequency distortion.

Tip: It is also advisable to apply an anti-aliasing low-pass filter to an audio file prior to resampling to a lower sample rate.

Set the sample rate only (do not resample)

If the Set the sample rate only check box is selected, the playback rate is changed without resampling the data. This means that the pitch of the original file is not preserved. For this reason, this option is only useful for quickly converting between two similar sample rates.

Reverse

The Reverse command reverses the audio selection.

1.Open the Musicbed.pca file.

2.From the Process menu, choose Reverse. The reversed audio data displays in the data window.

Original audio data

Reversed audio

Smooth/Enhance

If you are working with the full version of Sound Forge, choosing Smooth/Enhance from the Process menu starts Sony Pictures Digital’s XFX Smooth/Enhance plug-in. For more information on using the XFX Smooth/Enhance plug-in, refer to Sound Forge online help (from the Help menu, choose Contents and Index).

If you are using Screenblast Sound Forge, choosing Smooth/Enhance from the Process menu starts Sound Forge’s native version of the effect.

CHP. 10

PROCESSING AUDIO