Viewing a Sonogram

Click the Sonogram button in the Spectrum Analysis window to display spectrum information as a sonogram.

The sonogram displays time along the X (horizontal) axis and frequency along the Y (vertical) axis. The amplitude of each frequency is represented by the intensity of the color.

Generate a sonogramClosed

  1. Select the portion of the waveform you want to analyze. The sound or note you want to analyze should be in the center of the highlighted area.

    IMPORTANT Analyzing long sections of audio can take a long time and decreases the time resolution, so your selection should be relatively short. Also, if the audio has a low amplitude level, you can boost it by using the Volume or Normalize functions.

  1. From the View menu, choose Spectrum Analysis to show the Spectrum Analysis window if it isn't already visible.

  2. Click the Sonogram button in the Spectrum Analysis window to display spectrum information as a sonogram.

  3. Use the toolbar at the top of the window to set your display options.
    You can also click the Settings button in the Spectrum Analysis window to set additional options.

TIP You will often have to experiment with different parameters in the Spectrum Settings dialog to get the best graph possible. Try to narrow the frequency and amplitude ranges as much as possible to achieve large contrasts. If the graph is too chunky, increase the Set sonogram resolution setting to approximately 200. For more frequency resolution, increase the FFT Size. To decrease processing times, decrease the number of samplings or the FFT Size.

Adjust color and intensity Closed

  1. Click the down arrow next to the Sonogram button and choose Color or Black and White from the menu to specify whether you want to view a color or black-and-white sonogram.
    A separate sonogram is displayed for each channel in the active data window.

  2. Drag the slider below each sonogram to adjust the color intensity of the display. The bottom-right corner of the window will show the color scale in dB.

View frequency, amplitude, notes, and statisticsClosed

As you move the cursor through the sonogram, the amplitude and frequency values at the current position are displayed in a ToolTip next to the cursor and in the Statistics area at the bottom of the window:

If you want to display the nearest musical note equivalent of the cursor position in a ToolTip, right-click the graph and choose Show Notes from the shortcut menu:

Right-click the Spectrum Analysis window and choose Show Statistics from the shortcut menu to toggle the display of the Statistics area at the bottom of the Spectrum Analysis window.

Synchronize graphs in a multichannel file Closed

If you are analyzing a multichannel file, click the Sync button to synchronize the displays so you can view the same region of the FFT in all channels.

Use a sonogram to find the fundamental frequency of a sound Closed

  1. Select the portion of the waveform you want to analyze. The sound or note you want to analyze should be in the center of the highlighted area.

  1. From the View menu, choose Spectrum Analysis to show the Spectrum Analysis window if it isn't already visible.

  2. Click the Sonogram button in the Spectrum Analysis window to display spectrum information as a sonogram.

  3. Click the down arrow next to the Sonogram button and choose Color from the menu.

    The sound you want to analyze should be displayed in shades of red. Hover over the center of the area to display the fundamental frequency.

    If upper harmonics exist, they will be displayed as less intense red area above the fundamental, and will usually be multiples of the fundamental (a note at 440 Hz played on an instrument with fairly predictable or even harmonic content will have strong upper harmonics at 880 Hz and 1.76 kHz).

TIP After isolating a sound's fundamental frequency, you can use equalization to emphasize or attenuate the sound.

Print the graph Closed

Click the Print button to print the contents of the Spectrum Analysis window, including the graph and summary data.

Refresh the graph Closed

Select the Auto Refresh button if you want the Spectrum Analysis display to refresh automatically when you change your selection in the data window.

When the button is not selected, the display is not updated until you click the Refresh button .

Turn on real-time input monitoring Closed

Click the Real Time Monitoring button to turn real-time spectrum analysis on or off. Click the down arrow next to the button and choose a command from the menu to specify whether you want to monitor your sound card's input:

  • When you choose Monitor Input, Sound Forge Pro will monitor the recording devices selected on the Record page of the Audio tab in the Preferences dialog.

  • When you choose Monitor Output, a cursor is displayed in the sonogram to indicate the play position (real-time output monitoring is not available in sonogram display mode).