Viewing selection statistics

Choosing Statistics from the Tools menu displays a Statistics window showing information about the current selection or, if there is no selection, on the entire file.

The following table describes all statistical categories displayed in the Statistics window.

Statistical Category

Description

Ruler Format

Choose a setting from the drop-down list to determine the format you would like to

 

use for the Cursor position, Minimum sample position, and Maximum sample

 

position categories. For more information, see Selecting status formats on page 80.

 

 

Level Format

Choose a setting from the drop-down list to specify how the left- and right-channel

 

levels at the cursor position will appear.

 

• Values Appears as an integer. The range is from -8388608 to 8388607 in 24-bit

 

audio, -32768 to 32767 in 16-bit audio and -128 and 127 in 8-bit audio.

 

• Decibels Appears as decibels. A value of 0 dB corresponds to maximum absolute

 

amplitude and negative infinity (-Inf.) corresponds to complete silence. In 16-bit

 

audio, -90.3 dB is the lowest possible dB value (sample value of 1).

 

• Percentages Appears as a percentage ranging from -100 to 100 percent.

 

 

Cursor position

The cursor position (in samples) from the start of the audio file.

 

 

Sample value at cursor

The actual number stored by a single sample. The maximum allowed sample value is

 

often referred to as 100% or 0 dB.

 

 

Maximum/minimum sample

The maximum and minimum sample values and the locations (in samples) where they

position and sample value

occur.

 

These values may help determine if clipping will occur in the audio file. These values

 

can also be used to determine the noise level of a signal for use with the Noise Gate

 

effect (a built-in XFX plug-in installed with Sound Forge). For example, to determine

 

the noise amplitude of a file, run Statistics on a region of noisy silence.

 

 

RMS level

The Root Mean Square of the sample values relative to the RMS value of a maximum-

 

amplitude square wave (the loudest possible recording).

 

On short intervals, this value relates to the volume level of the audio file. If used on a

 

large selection with large volume variation, this value becomes less meaningful.

 

 

Average value

The sum of all sample values in the selected region divided by the number of samples.

 

If this value is not zero, it usually indicates a DC offset in the recording process.

 

 

Zero crossings

The number of times per second that the waveform fluctuates from a negative to a

 

positive value.

 

This value can be used as a rough estimate of the frequency of the audio data for very

 

simple waveforms.

 

 

Copy to Clipboard

Copies all contents of the Statistics window to the clipboard. This can be useful if you

 

want to compare statistics of multiple files in a spreadsheet.

 

Note: To copy specific data or cells, select the cells that you want to copy and press

 

Ctrl+C.

 

 

64 CHAPTER 3