audacity-manual/manual/man/label_sounds.html
2025-12-04 12:24:42 +00:00

242 lines
22 KiB
HTML

<!DOCTYPE html>
<html class="client-nojs" lang="en" dir="ltr">
<head>
<meta charset="UTF-8"/>
<title>Label Sounds - Audacity Manual</title>
<meta name="ResourceLoaderDynamicStyles" content=""/>
<meta name="generator" content="MediaWiki 1.28.2"/>
<link rel="shortcut icon" href="../favicon.ico"/>
<link rel="search" type="application/opensearchdescription+xml" href="https://alphamanual.audacityteam.org/m/opensearch_desc.php" title="Audacity Development Manual (en)"/>
<link rel="EditURI" type="application/rsd+xml" href="https://alphamanual.audacityteam.org/m/api.php?action=rsd"/>
<link rel="copyright" href="http://creativecommons.org/licenses/by/3.0/"/>
<link rel="stylesheet" href="../m/skins/monobook/main.css/303.css" media="screen" />
</head>
<body class="mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject page-Label_Sounds rootpage-Label_Sounds skin-monobook action-view"><div id="globalWrapper">
<div id="column-content">
<div id="content" class="mw-body" role="main">
<a id="top"></a>
<div class="mw-indicators">
</div>
<h1 id="firstHeading" class="firstHeading" lang="en">Label Sounds</h1>
<div id="bodyContent" class="mw-body-content">
<div id="siteSub">From Audacity Development Manual</div>
<div id="contentSub"></div>
<div id="jump-to-nav" class="mw-jump">Jump to: <a href="#column-one">navigation</a>, <a href="https://alphamanual.audacityteam.org/man/Label_Sounds#searchInput">search</a></div>
<div id="mw-content-text" lang="en" dir="ltr" class="mw-content-ltr"><div class="intro"><i><b>Label Sounds</b></i> is a tool which can useful to label the different songs or sections (or silences) in a long recording, such as the tracks from an LP or cassette.
<div class="note">This analyzer is an upgrade of the old "Sound Finder" from previous versions of Audacity. It is more accurate, and more versatile than previous versions, supporting both region labels and point labels.<p>It replaces <a href="sound_finder.html" title="Sound Finder">Sound Finder</a> and <a href="silence_finder.html" title="Silence Finder">Silence Finder</a></p></div> </div>
<div id="sound"></div>
<dl><dd><b>Accessed by:</b> <span class="menu">Analyze &gt; Label Sounds</span></dd>
<dd><span title="Label Sounds dialog"><img alt="Label Sounds 3-5-0.png" src="../m/images/8/8f/label_sounds_3_5_0.png" width="571" height="376" /></span></dd></dl>
<p><br />
<b>Label Sounds</b> detects the audio level in the selected track(s). When the track level exceeds a specified threshold level, the audio is considered to be "sound", and when below the level it is considered to be "silence".
</p><p>There are options to add point labels before or after each detected sound, region labels around each sound, or region labels between each sound (effectively labeling the silences).
</p>
<div class="note">The audio is processed in 10 ms chunks, (intervals of 0.01 seconds), thus the label placement may be up to 0.01 seconds before / after a sound.</div>
<p>Normally the effect would be applied to a single track. If multiple tracks are selected, each track is processed in turn and all of the labels will be produced in a single label track.
</p>
<div style="margin-top:12px; margin-bottom:12px; margin-left:24px; margin-right:24px">
<table style="background:#FEFFD0; color:black; border:1px solid #999999; padding-left:12px; padding-right:12px" width="100%" align="center">
<tr>
<td width="30px" valign="top" align="center"><img alt="Tip" src="../m/images/d/d7/bulbicon.png" title="Tip" width="32" height="32" />
</td>
<td align="left" valign="top">"Label Sounds" is intentionally limited to a maximum of 10000 labels. <p>In the unlikely event that you need to create more labels, process the track in sections, but be aware that Audacity may become sluggish with a very large number of labels.</p>
</td></tr></table>
</div>
<p><br />
</p>
<h2><span class="mw-headline" id="Controls:">Controls:</span></h2>
<ul><li><b>Threshold level (dB):</b> (default -30 dB) </li></ul>
<dl><dd> When audio is below this level, it is considered to be 'silence'. The lower (more negative) this setting, the quieter the background level must be to be recognized as "silent". If set below the track's noise floor level, the entire track will be seen as one continuous sound.</dd></dl>
<ul><li><b>Threshold measurement:</b> (default "Peak level")
<ul><li> <b>Peak level:</b> The threshold measurement is based on the <a rel="nofollow" class="external text" href="https://en.wikipedia.org/wiki/Amplitude#Peak_amplitude">peak amplitude</a> in each 10ms period.</li>
<li><b>Average level:</b> The threshold is measured as the absolute average level for each 10 ms. This setting may help avoid labeling clicks in vinyl recording. Note that the average level will usually be lower than the peak level.</li>
<li><b>RMS level:</b> The threshold is measured as RMS level. Like the 'Average level' measurement, this is less likely to label clicks. RMS level may be measured with the 'Measure RMS' or 'Contrast' effects.</li></ul></li></ul>
<ul><li><b>Minimum silence duration:</b> (default 1 second)</li></ul>
<dl><dd> When 'silence' of this duration (or longer) is found, preceding sound and following sound are considered to be separate sounds, provided that the previous sound is at least the 'Minimum sound duration'. Valid values are between 0.01 seconds to 1 hour. See <a href="#Minimum_Silence_Duration">examples below</a>.</dd></dl>
<ul><li><b>Minimum label interval:</b> (default 1 second)</li></ul>
<dl><dd> This is effectively the minimum length of a sound duration, it allows short sounds to be grouped within a label region. This ensures that labels will be at intervals of no less than this length. In effect this combines short sounds to create a group of sounds that is at least the specified length. Valid values are between 0.01 seconds to 2 hours. See <a href="#Minimum_label_interval">examples below</a>.</dd></dl>
<ul><li><b>Label type:</b> (default: Region around sounds) Sounds / silences are labelled either with <a href="label_tracks.html#type" title="Label Tracks">point labels</a> or <a href="label_tracks.html#type" title="Label Tracks">region labels</a>.
<ul><li><b>Point before sound</b> This option places a point label <i>before</i> each detected sound or group of sounds.</li>
<li><b>Point after sound</b> This option places a point label <i>after</i> each detected sound or group of sounds.</li>
<li><b>Region around sounds</b> This option places a region label <i>around</i> each detected sound or group of sounds.</li>
<li><b>Region between sounds</b> This option places a region label <i>between</i> each detected sound or group of sounds. In effect this labels silent regions.</li></ul></li></ul>
<ul><li><b>Maximum leading silence:</b> (default: 0 seconds)
<ul><li> When labeling <i>sounds</i>, a point label, or the start of a region label will be placed before the beginning of the sound by up to this amount. If there is insufficient room to do so without overlapping a previous sound, this distance is automatically reduced. Labels will not be placed before time=0 and will not overlap previous sounds.</li>
<li> When labeling the silent <i>regions between sounds</i>, a point label, or the start of a region label will be offset by this amount after the end of the previous sound. See <a href="#Maximum_leading_.2F_trailing_silence">examples below</a>.</li></ul></li></ul>
<ul><li><b>Maximum trailing silence:</b> (default 0 seconds)</li></ul>
<dl><dd> This setting is used by region labels only.
<ul><li> When labeling <i>sounds</i>, the end of a region label will be placed this distance after the end of a sound, provided that there is room to do so before the next sound.</li>
<li> When labeling the silent <i>regions between sounds</i>, the end of a region label will be placed this distance before the start of the next sound, provided there is room to do so. If the combined length of <b>Maximum leading silence</b> and <b>Maximum trailing silence</b> is longer than the space between the previous and next sounds, then a point label is created. See <a href="#Maximum_leading_.2F_trailing_silence">examples below</a>.</li></ul></dd></dl>
<ul><li><b>Label text:</b> (default "Sound ##1")</li></ul>
<dl><dd> This is the text that will be entered in each label.
<ul><li> The '#' symbol is a special 'placeholder' character for adding a counter. The number of successive '#' symbols determines the minimum number of digits to be displayed. The '#' symbols must be followed by an integer (whole) number, which sets the starting number. Example: ###3 will add a three digit counter that counts up: 003, 004, 005... for consecutive labels. A counter may be placed before, after or withing the label text, but only one counter may be used in a label.</li></ul></dd></dl>
<p><br />
</p>
<div id="tips"></div>
<h2><span class="mw-headline" id="Tips">Tips</span></h2>
<ul><li> If the 'Threshold' is set too low, then 'silences' may be above the Threshold level, causing the 'silence' to be seen as a 'sound'.</li>
<li> If the 'Threshold' is set too high, the beginning or end of sounds may be missed.</li>
<li> If 'Minimum silence duration' is too short, there may be more labels than intended due to short gaps being seen as 'silence'.</li>
<li> If 'Minimum silence duration' is too long, gaps between songs may not be seen.</li>
<li> For vinyl recordings, 'Average' or 'RMS' measurement is recommended so as to reduce the chance of crackles registering as 'sounds'.</li>
<li> When <a href="splitting_a_recording_into_separate_tracks.html" title="Splitting a recording into separate tracks">splitting a recording into separate tracks</a>, it may be useful to set the <b>Label text</b> to <span style="line-height:1.1em;letter-spacing:-0.04em;background-color:#FDEEF4;padding:3px;font-family:monospace;font-size:1.1em;border:1px dashed black">Name of Album ##1</span> and then ues <span class="menu">File &gt; <a href="file_export_dialog.html" title="File Export Dialog">Export Audio</a></span> and selecting <a href="export_multiple.html" title="Export Multiple">Multiple Files</a> using it based on labels using the label names for file names.</li></ul>
<p><br />
</p><p><br />
</p>
<div id="examples"></div>
<h2><span class="mw-headline" id="Examples">Examples</span></h2>
<div class="intro">In these examples, all settings are at default values except for the settings mentioned in the example.</div>
<h3><span class="mw-headline" id="Minimum_Silence_Duration">Minimum Silence Duration</span></h3>
<div class="example">In this example, the first silence is 2 seconds, the second silence 5 seconds, and the final silence 1 second.
<ul><li><b>Minimum Silence Duration: 4.000 seconds</b></li></ul>
<p><img alt="Label-sounds-min-silence.png" src="../m/images/e/e0/label_sounds_min_silence.png" width="886" height="270" />
</p>
<ul><li>Observe that first and last silences are ignored because they are each less than 4 seconds. The middle silence is 5 seconds duration, so this is recognized as a gap between two sounds.</div></li></ul>
<h3><span class="mw-headline" id="Minimum_label_interval">Minimum label interval</span></h3>
<p>For clarity, this is what is meant by the "label interval", what is in effect the sound duration.
</p>
<dl><dd><img alt="Label interval.png" src="../m/images/f/f9/label_interval.png" width="690" height="191" /></dd></dl>
<div class="example">In this example, each sound and each silence are about 1.76 seconds long.
<ul><li><b>Minimum label interval: 10.000 seconds</b></li></ul>
<p><img alt="Label-sounds-min-interval.png" src="../m/images/b/b5/label_sounds_min_interval.png" width="886" height="262" />
</p>
<ul><li>Observe that the first 4 sounds are grouped together, creating label "Sound 01" which is about 12.4 seconds long.</li>
<li>The next label, "Sound 02" begins at the start of the next sound, and groups the next 4 sounds, with a label region of about 12.4 seconds.</li>
<li>The final label, "Sound 03" begins at the start of the next sound, and ends at the end of the selection. This is exempt from the "10 second minimum" because it has reached the end of the selected audio.</div></li></ul>
<h3><span class="mw-headline" id="Label_type">Label type</span></h3>
<div class="example">In this example, each label track was created with default settings other than "Label type" and "Label text" settings.
<ol><li>The first label track: <b>Label type: Point before sound</b></li>
<li>The second label track: <b>Label type: Point after sound</b></li>
<li>The third label track: <b>Label type: Region around sounds</b></li>
<li>The fourth label track: <b>Label type: Region between sounds</b></li></ol>
<img alt="Label-sounds-types.png" src="../m/images/7/71/label_sounds_types.png" width="886" height="479" /></div>
<h3><span class="mw-headline" id="Maximum_leading_.2F_trailing_silence">Maximum leading / trailing silence</span></h3>
<div class="example">In this example, the gaps are 5 seconds, 2 seconds and 3 seconds.
<ul><li> <b>Maximum leading silence: 2.5 seconds</b></li>
<li> <b>Maximum trailing silence: 0 seconds</b></li></ul>
<p><img alt="Label-sounds-leading.png" src="../m/images/c/c9/label_sounds_leading.png" width="886" height="258" />
</p>
<ul><li> Observe that the first label "Sound 01" starts at the beginning of the track. Labels will not be created before time = 0.</li>
<li> The second label, "Sound 02" begins 2.5 seconds before the start of the second sound.</li>
<li> The third label,"Sound 03" would overlap the previous sound if it started 2.5 seconds before the start of the third sound, but overlapping the previous sound is disallowed. This label therefore starts as early as possible - at the end of the second sound.</li>
<li> The final label, "Sound 04" has sufficient room to start 2.5 seconds before the start of the final sound.</div></li></ul>
<p><br />
</p>
<div class="example">In this example, the gaps are 5 seconds, 2 seconds and 3 seconds.
<ul><li> <b>Maximum leading silence: 2.5 seconds</b></li>
<li> <b>Maximum trailing silence: 2.5 seconds</b></li></ul>
<p><img alt="Label-sounds-leading-trailing.png" src="../m/images/d/d9/label_sounds_leading_trailing.png" width="886" height="261" />
</p>
<ul><li>Observe that labels <i>can</i> overlap other labels, but <i>cannot</i> overlap previous or following sounds.</li>
<li>Notice also that the final label extends 2.5 seconds beyond the end of the final sound, even though it is beyond the end of the track.</div></li></ul>
<p><br />
</p>
<div class="example">In this example, the gaps are 5 seconds, 2 seconds and 3 seconds.
<ul><li> <b>Maximum leading silence: 1 second</b></li>
<li> <b>Maximum trailing silence: 1 second</b></li>
<li> <b>Label type: Region between sounds</b></li>
<li> <b>Label text: Silence ##1</b></li></ul>
<p><img alt="Label-between-sounds-leading-trailing.png" src="../m/images/2/2a/label_between_sounds_leading_trailing.png" width="886" height="264" />
</p>
<ul><li> Observe that the labels are between sounds</li>
<li> The start of each label is 1 second after the previous sound</li>
<li> The end of each label is 1 second before the next sound</li>
<li> The second label, "Silence 02" is collapsed down to a point label</div></li></ul>
<h2><span class="mw-headline" id="Links">Links</span></h2>
<p><a href="index_of_effects_generators_and_analyzers.html#analyzers" title="Index of Effects, Generators and Analyzers"><b>|&lt;</b> Index of Effects, Generators and Analyzers</a>
</p><p><a href="analyze_menu.html" title="Analyze Menu"><b>|&lt;</b> Analyze Menu</a>
</p>
</div>
<div class="visualClear"></div>
</div>
</div>
</div>
<div id="column-one">
<div class="portlet" id="p-logo" role="banner">
<a href="../index.html" class="mw-wiki-logo" title="Visit the main page"></a>
</div>
<div class="generated-sidebar portlet" id="p-Navigation" role="navigation">
<h3>Navigation</h3>
<div class='pBody'>
<ul><li> <a href="../index.html" title="Main Page"><span title="Front page, complete with clickable image of Audacity screen.">Manual Home Page</span></a>
<ul><li> <a href="audacity_tour_guide.html" title="Audacity Tour Guide"><span title="A quick tour of selected features of Audacity. It doesn't tell you how to use features it would be much too long if it did. Rather it tells you about some of the features that exist in Audacity and will help you learn a little about those.">Tour Guide</span></a></li></ul></li>
<li> <a href="how_to_use_audacity.html" title="How to use Audacity"><span title="Quick Help, Audacity Foundations, Editing with Audacity, Help with Advanced Topics">Using Audacity</span></a>
<ul><li> <a href="../quick_help.html" title="Quick Help"><span title="A brief guide to help you get started with Audacity">Getting Started</span></a></li>
<li> <a href="how_to_use_audacity.html" title="How to use Audacity"><span title="A comprehensive guide to using Audacity">How-Tos</span></a></li>
<li> <a href="tutorials_for_audacity.html" title="Tutorials for Audacity"><span title="A guide to the tutorials that provide step-by-step instructions for performing common tasks in Audacity">Tutorials</span></a></li>
<li> <a href="tips.html" title="Tips"><span title="A guide to particular aspects of working with Audacity: Navigation. Playback, Audio Alignment">Tips</span></a></li></ul></li>
<li> <a href="../index.html#reference" title="Main Page"><span title="The components of the Audacity Graphical User Interface">Audacity GUI</span></a>
<ul><li> <a href="menu_reference.html" title="Menu Reference"><span title="A guide to the menus and submenus in Audacity">Menu Bar</span></a></li>
<li> <a href="toolbars_overview.html" title="Toolbars Overview"><span title="A guide to the various Toolbars used in Audacity">Toolbars</span></a></li>
<li> <a href="audio_tracks.html" title="Audio Tracks"><span title="A guide to the various types of track">Tracks</span></a></li>
<li> <a href="index_of_effects_generators_and_analyzers.html" title="Index of Effects, Generators and Analyzers"><span title="A quick index to the Effects, Generators and Analyzers that are shipped with Audacity">Effects</span></a></li></ul></li>
<li> <a href="customization.html" title="Customization"><span title="Adjust settings, change keyboard shortcuts, add plugins">Customizing</span></a>
<ul><li> <a href="preferences.html" title="Preferences"><span title="A guide to Preferences, which let you change most of the default behaviors of Audacity">Preferences</span></a></li>
<li> <a href="keyboard_shortcut_reference.html" title="Keyboard Shortcut Reference"><span title="A list of all the commands in the Audacity menus and all pre-defined keyboard shortcuts">Shortcut keys</span></a></li>
<li> <a href="customization.html#plugins" title="Customization"><span title="You can download and install plugins to add extra functionality to Audacity. Plugins can give you extra effects, or more audio generation and analysis capability.">Plugins</span></a></li>
<li> <a href="themes.html" title="Themes"><span title="Audacity now comes supplied with four pre-configured, user-selectable themes. This enables you to choose the look and feel you prefer for Audacity&#39;s interface.">Themes</span></a></li>
<li> <a href="customizing_toolbar_layout.html" title="Customizing Toolbar Layout"><span title="Audacity&#39;s toolbars can all be re-positioned (in the tooldocks or free-floating) and some can be resized.">Toolbars</span></a></li>
<li> <a href="manage_effects_generators_and_analyzers.html" title="Manage Effects, Generators and Analyzers"><span title="Manage your list of available built-in Effects, Generators, Analyzers and plugins with the Plugin Manager">Effects</span></a></li></ul></li></ul>
</div>
</div>
<div class="generated-sidebar portlet" id="p-Reference" role="navigation">
<h3>Reference</h3>
<div class='pBody'>
<ul><li> <a href="../index.html#reference" title="Main Page"><span title="Reference guide to the Audacity project window - you can hover over and click on the image to learn more">Reference</span></a>
<ul><li> <a href="searching_the_manual.html" title="Searching the Manual"><span title="Tips on how to Search the Audacity Manual">Search the Manual</span></a></li>
<li> <a href="digital_audio.html" title="Digital Audio"><span title="A beginner&#39;s guide to digital audio">Digital Audio</span></a></li>
<li> <a href="glossary.html" title="Glossary"><span title="Brief explanations of technical terms related to digital audio, with some links to Wikipedia for much more comprehensive explanations">Glossary</span></a></li>
<li> <a href="scripting_reference.html" title="Scripting Reference"><span title="Audacity Commands that are in menus, that can be used from Macros, Nyquist and Python">All Commands</span></a></li>
<li> <a href="faq_errors.html" title="FAQ:Errors"><span title="FAQ on common errors encountered when using Audacity">Errors</span></a></li>
<li> <a href="subject_index.html" title="Subject Index"><span title="A short, limited, index of the Manual">Index</span></a></li></ul></li>
<li> <a href="faq.html" title="FAQ"><span title="Frequently Asked Questions - most common questions are answered in the FAQ">FAQ</span></a></li></ul>
</div>
</div>
<div class="generated-sidebar portlet" id="p-Useful_Links" role="navigation">
<h3>Useful Links</h3>
<div class='pBody'>
<ul><li> <span title="Audacity Forum (best place for support requests)"><a rel="nofollow" class="external text" href="https://forum.audacityteam.org/">Forum</a></span></li>
<li> <span title="Audacity Wiki Home Page"><a rel="nofollow" class="external text" href="https://support.audacityteam.org/">Audacity Support</a></span></li>
<li> <span title="Audacity Latest Release"><a rel="nofollow" class="external text" href="https://www.audacityteam.org/download/">Latest Release</a></span></li></ul>
</div>
</div>
</div>
<div class="visualClear"></div>
<div id="footer" role="contentinfo">
<div id="f-copyrightico">
</div>
<div id="f-poweredbyico">
<a href="https://www.mediawiki.org/"><img src="../m/resources/assets/poweredby_mediawiki_88x31.png" alt="Powered by MediaWiki" srcset="/m/resources/assets/poweredby_mediawiki_132x47.png 1.5x, /m/resources/assets/poweredby_mediawiki_176x62.png 2x" width="88" height="31"/></a>
</div>
<div align="center"><ul id="f_list"><li>This version created on 2025-12-04 - <a href="https://alphamanual.audacityteam.org/man/Label_Sounds">Check current version of this page (development Manual)</a></li></ul></div>
</div>
</div>
</body></html>