User:Stevethefiddle

=Steve Daulton's user page= First draft of manual page for proposed Sound Finder enhancements.

=Sound Finder...= The Sound Finder dialog appears in response to the Analyze > Sound Finder... command. Sound Finder divides a track up by placing region labels for areas of sound that are separated by silence.
 * [[Image:AdvancedSoundFinder.png|Sound Finder dialog]]

Common Uses

 * When splitting a recording into tracks for burning to an audio CD, Sound Finder may be used to label tracks prior to exporting with Export Multiple.
 * Large files may be split into smaller files for convenient uploading to the Internet or listening on portable media players.
 * Brief sounds in quiet environmental recordings may be easily identified and labeled.
 * Audio books and lectures may be split into convenient sized sections.

Controls

 * Threshold for silence: The level (dB) at which the plug-in determines if the audio is sound or silence. To detect quieter sounds set this control to a lower value (default -24 dB). To only detect louder sounds set this control to a higher level.


 * Threshold detection method: Options: Peak Level (default) or RMS Level. The RMS level detection method may be useful when labeling sounds from vinyl recordings as it will tend to ignore short crackles that may be present in the gaps between tracks. When using this mode the Threshold for silence control will need to be set somewhat lower than for the peak level detection method.


 * Allow gaps in sound less than: default 1.0 seconds. Gaps that occur within a sound that are shorter than this are in effect "ignored". This prevents recordings from being split at brief gaps between musical notes, between words, or other short gaps.


 * Disregard isolated sounds less than: default 0.0 seconds, which does not disregard isolated sounds. To prevent short sounds that occur within otherwise silent regions from being labeled, increase this setting so that it is slightly greater than the duration of the sounds that you wish to disregard.


 * Minimum label length (optional): default 0:0.000 minutes:seconds (no minimum). Note that this control uses text input:
 * A single number may be entered to set the number of second. This may be a whole number or a decimal, for example 2.5 will be read as two and a half a seconds.
 * Two numbers may be entered to set the value in minutes and seconds. The two numbers must be separated by either a space or a colon (:). To enter a time in minutes there must be two numbers entered as a single number will be interpreted as seconds.
 * This optional control can be especially useful for splitting lectures, sermons, audio books and similar material. If the Threshold and Gap settings are first adjusted so that gaps between words are detected, then this control can be used to combine the detected words into longer groups.


 * Label starting point (before start of sound): default 0.1 seconds. The start of the region label will be positioned this distance before the start of the detected sound.


 * Label ending point (after end of sound): default 0.1 seconds. The end of the region label will be positioned this distance after the end of the detected sound.


 * Begin numbering from: default 1. Any whole number may be entered by keyboard input. If the label are numbered, they will be numbered sequentially starting at this number. For example, to number the labels 0, 1, 2... set this to 0, or to number the labels 1, 2, 3... set this to 1.


 * Minimum number of digits: default 2. It is often convenient to number all of the labels with the same number of digits so as to preserve alpha-numeric ordering. With the default setting, single digit numbers will be padded with a preceding zero to two digits 01, 02, 03...


 * Label text (optional): default "Track_". Either in addition to, or instead of the label number, a word or phrase may be used in the label text. This text is only used if enabled in the Label options.


 * Label options: default "Text & Number". This determines whether labels are numbered and/or use the optional Label text. The available options are:
 * Number only, for example 001, 002, 003,...
 * Text only, for example: sound, sound, sound...
 * Number & Text, for example: 21noise, 22noise, 23noise...
 * Text & Number, for example: Track_01, Track_02, Track_03...

Detection
The audio track is scanned, looking at the level of the audio. Audio that is above the threshold level is classed as sound. Audio that is below the threshold level is classed as silence.


 * If Click filter is enabled, sounds that are less than a few milliseconds are disregarded.
 * If Hiss filter is enabled, very high frequencies are attenuated before the analysis.
 * If Rumble filter is enabled, very low frequencies are attenuated before analysis.

Sound Finder makes a distinction between "valid" and "invalid" sound by taking into account the duration of the detected sound. Gaps in a sound that are shorter than the "allowed" gaps are disregarded. The length of "allowed" gaps is set by the "Allow gaps less than (seconds)" control. The length of each section of audio (disregarding small gaps) is then examined and if longer than Minimum sound length it is counted as "valid sound".

Sound Finder then looks at the gaps (silences) between the "valid sounds". (Note that if the Click filter was enabled, the silences may already contain short peaks of sound). If the detected silences are longer than Minimum silence length they are counted as "valid silences".

Stereo Tracks
When analysing stereo tracks, the left and right channels are mixed in a special way, such that the analysed sound is the maximum of the left and right channels. Thus, a gap in the audio will be detected only where it is common to both left and right channels.

Multiple Selected Tracks
If multiple audio tracks are selected, they are processed separately and a set of labels will be produced for each track. Due to a limitation in the version 3 Nyquist interface it is not possible to create multiple label tracks in one pass. If multiple label tracks are required, the tracks must be analyzed one at a time.

Usage Tips

 * If you simply want to mark gaps between sounds without the advanced features of this effect, try the Silence Finder... tool.


 * If low level sounds are not detected, try lowering the Threshold for silence.


 * If gaps between sounds are not recognized, try raising the Threshold for silence or reducing the Allow gaps setting.


 * When splitting a album or tape transfer into "songs", if any of the songs have more than one label, try increasing the silence threshold and/or allowed gap duration. If any labels extend into other tracks, try reducing those settings.