{"id":2255,"date":"2024-06-10T13:11:43","date_gmt":"2024-06-10T19:11:43","guid":{"rendered":"https:\/\/blog.faberacoustical.com\/wpblog\/?p=2255"},"modified":"2024-06-10T13:24:31","modified_gmt":"2024-06-10T19:24:31","slug":"how-to-analyze-audio-files-with-signalscope","status":"publish","type":"post","link":"https:\/\/blog.faberacoustical.com\/wpblog\/2024\/mac\/tutorials-mac\/how-to-analyze-audio-files-with-signalscope\/","title":{"rendered":"How to Analyze Audio Files with SignalScope"},"content":{"rendered":"\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"How to Analyze Audio Files with SignalScope (Gunshot Sound Directivity Recordings)\" width=\"860\" height=\"484\" src=\"https:\/\/www.youtube.com\/embed\/TVVWOm_3MAA?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<p>This video shows how to use the MultiTool in SignalScope X to analyze data in an audio file (WAV, AIF, or CAF) using SignalScope&#8217;s File Player and Octave Analyzer tools. As an example, a file containing gunshot recordings is analyzed as part of a project to measure the directional nature of gunshot sounds. (Some features shown in this video require the Pro Tool Set.)<\/p>\n\n\n\n<p>SignalScope apps mentioned (SignalScope X version 12.4 was used in this video):<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/www.faberacoustical.com\/apps\/signalscope\/signalscope_x\/\">SignalScope X<\/a> (Cross Platform, Subscription)<\/li>\n\n\n\n<li><a href=\"https:\/\/www.faberacoustical.com\/apps\/signalscope\/xm\/\">SignalScope XM<\/a> (Mac only, Perpetual License)<\/li>\n\n\n\n<li><a href=\"https:\/\/www.faberacoustical.com\/apps\/signalscope\/signalscope_pro_2022\/\">SignalScope Pro 2022<\/a> (Cross Platform, Perpetual License)<\/li>\n<\/ul>\n\n\n\n<p><strong>Transcript<\/strong><\/p>\n\n\n\n<p>********** Intro (00m 07s)<\/p>\n\n\n\n<p>This video will demonstrate how to analyze data stored in audio files using the Audio File Player and the MultiTool.<\/p>\n\n\n\n<p>Although the file player tool is available in the advanced tool set and can be used for analysis with the other tools in that set, we&#8217;ll show, here, that the best way to analyze audio files is with the MultiTool, which requires the Pro Tool Set.<\/p>\n\n\n\n<p>You can follow along with this video in SignalScope X or SignalScope XM, with the Pro Tool Set, or with SignalScope Pro 2022.<\/p>\n\n\n\n<p>The instructions, here, will work whether you&#8217;re running SignalScope on your Mac, iPad or iPhone.<\/p>\n\n\n\n<p>Note that tool selection is on the left-hand side of the window, instead of the bottom, if you&#8217;re on a Mac.<\/p>\n\n\n\n<p>********** MultiTool Configuration (00m 49.3s)<\/p>\n\n\n\n<p>To get started, let&#8217;s select the MultiTool and create a new measurement configuration.<\/p>\n\n\n\n<p>We do that by opening up the tools options menu, entering a name for the new configuration, and then pressing the return key, or the Done button on the virtual keyboard.<\/p>\n\n\n\n<p>This will create a new configuration with the new name.<\/p>\n\n\n\n<p>Now, let&#8217;s close the options menu and set up our measurement configuration.<\/p>\n\n\n\n<p>Since the new configuration is just a copy of the previous one, we&#8217;ll first remove whatever tools are there to make room for the new ones that we want.<\/p>\n\n\n\n<p>Now in this video, we&#8217;ll be analyzing some gunshot recordings that are part of a project to measure the directivity of gunshot sounds.<\/p>\n\n\n\n<p>We want to break the sounds down into individual third-octave frequency bands, so we&#8217;ll add an Octave Analyzer tool.<\/p>\n\n\n\n<p>Since the point, here, is to analyze the data contained in audio files, we&#8217;ll need to add the File Player tool.<\/p>\n\n\n\n<p>********** Player Configuration (01m 45.5s)<\/p>\n\n\n\n<p>Next, let&#8217;s configure the Player tool by loading an audio file.<\/p>\n\n\n\n<p>To do that, click on the import button.<\/p>\n\n\n\n<p>Now we see a list of locations we can add a file from.<\/p>\n\n\n\n<p>Local Configuration Folder refers to a measurement configuration folder belonging to the MultiTool.<\/p>\n\n\n\n<p>Local Folder refers to any folder belonging to SignalScope&#8217;s own documents directory.<\/p>\n\n\n\n<p>Music Library refers to available audio files contained within your music library.<\/p>\n\n\n\n<p>External Source refers to files stored elsewhere on your device or system.<\/p>\n\n\n\n<p>In this case, we want to load a file stored on iCloud Drive, so we&#8217;ll click the External Source and then browse to the desired file.<\/p>\n\n\n\n<p>So I&#8217;ve already got gunshots here in my favorites, so I&#8217;m gonna go ahead and load up the gunshot recordings at the zero degree angle.<\/p>\n\n\n\n<p>Once the file loads, you may see this message asking if you would like to automatically calibrate the selected output channels.<\/p>\n\n\n\n<p>This happens when SignalScope detects custom metadata embedded in the audio file containing channel calibration information.<\/p>\n\n\n\n<p>This custom metadata is embedded by the recorder tool in SignalScope or SoundMeter.<\/p>\n\n\n\n<p>In this case, the microphone units and sensitivity were saved by SignalScope when the gunshots were captured using a special measurement microphone.<\/p>\n\n\n\n<p>Since we want to perform calibrated measurements of the gunshot sound levels, let&#8217;s choose &#8216;YES.&#8217;<\/p>\n\n\n\n<p>Next, we need to configure our output channel selections.<\/p>\n\n\n\n<p>In the channel selection menu, we can see a list of output channels under each channel of data stored in the loaded audio file.<\/p>\n\n\n\n<p>The player tool lets us choose one or more of these physical or virtual output channels as a destination for the playback of the data in the file.<\/p>\n\n\n\n<p>Since we don&#8217;t want to play the gunshot through a speaker, let&#8217;s select a virtual output channel.<\/p>\n\n\n\n<p>The V at the end of the channel name indicates that it&#8217;s a virtual channel.<\/p>\n\n\n\n<p>We don&#8217;t need to route channel 2 anywhere since the gunshot data was only recorded in the first channel of the file.<\/p>\n\n\n\n<p>Now, if we look in the I\/O configuration menu, we can select output channels and see that the acoustic units and sensitivity information have been applied to our selected output channel.<\/p>\n\n\n\n<p>One more important point about configuring the file player tool is that we want the hardware sample rate to match the sample rate of the data in the file.<\/p>\n\n\n\n<p>If the sample rates don&#8217;t match, sample rate conversion will be used for playback.&nbsp;<\/p>\n\n\n\n<p>Since we&#8217;re making precision measurements, we want to avoid sample rate conversion.<\/p>\n\n\n\n<p>So in order to confirm the sample rate used by the audio file, click on the file info button in the Player tool.<\/p>\n\n\n\n<p>In this case, the gunshot data was sampled at 192 kilohertz.<\/p>\n\n\n\n<p>For convenience, we&#8217;ve already connected the RME ADI-2 Pro audio interface that was used for the original recordings.<\/p>\n\n\n\n<p>So we know it supports this sample rate.<\/p>\n\n\n\n<p>Let&#8217;s go back to the I\/O configuration menu to check the sample rate.<\/p>\n\n\n\n<p>Okay, the device is currently configured for 48 kHz.<\/p>\n\n\n\n<p>So let&#8217;s change the desired sample rate to 192k and then confirm that the actual sample rate has in fact changed.<\/p>\n\n\n\n<p>And, there it is.<\/p>\n\n\n\n<p>********** Octave Analyzer Configuration (04m 47.8s)<\/p>\n\n\n\n<p>Now let&#8217;s configure the Octave Analyzer tool for the measurements we want.<\/p>\n\n\n\n<p>First, let&#8217;s open up this tool&#8217;s channel selection menu and make sure we have the same output channel selected that we chose in the Player tool.<\/p>\n\n\n\n<p>In this case, virtual output channel three.<\/p>\n\n\n\n<p>But in this case, let&#8217;s turn off auto scale and manually set the scale to 12 dB per division, with a maximum value of 168 dB.<\/p>\n\n\n\n<p>Let&#8217;s also show a secondary level and set it to show peak levels.<\/p>\n\n\n\n<p>Next, we&#8217;ll set the sound level type to Leq with an indefinite averaging time.<\/p>\n\n\n\n<p>Then, we&#8217;ll enable auto stop and set the duration to the smallest available value of 100 milliseconds, since all we want to capture is a gunshot.<\/p>\n\n\n\n<p>We&#8217;ll also configure auto start triggering by switching it on, selecting our chosen output channel as the source, and then setting the threshold to an appropriate value.<\/p>\n\n\n\n<p>In this case, let&#8217;s set the threshold to 100 pascals, so the measurement will only start when the sound level exceeds 134 decibels.<\/p>\n\n\n\n<p>Finally, we&#8217;ll choose a pre-trigger delay of 20 milliseconds to be sure we don&#8217;t miss anything just before the level exceeds our threshold.<\/p>\n\n\n\n<p>********** Running the Measurement (06m 30s)<\/p>\n\n\n\n<p>Okay, now we&#8217;re ready to start our measurements.<\/p>\n\n\n\n<p>Click the start button at the top of the screen to begin playback and analysis of the data in the file.<\/p>\n\n\n\n<p>Okay, we&#8217;ve captured our first gunshot, so I&#8217;m gonna pause it.<\/p>\n\n\n\n<p>********** Saving the Measurement (06m 48s)<\/p>\n\n\n\n<p>Now, once the measurement is captured, we could save the measurement to a data file.<\/p>\n\n\n\n<p>To do that, click the action or share button in the top toolbar and select the desired option.<\/p>\n\n\n\n<p>In this case, we&#8217;ll click &#8220;Save All Data.&#8221;<\/p>\n\n\n\n<p>Now, we can edit the name and the type of the data file.<\/p>\n\n\n\n<p>We can also choose to have the data, saved in the file, loaded right back into the analyzer by switching on the switch labeled &#8220;Keep Data In Plot.&#8221;<\/p>\n\n\n\n<p>Also, since we&#8217;re using the Pro Tool Set, we can add custom metadata to the file.<\/p>\n\n\n\n<p>So, let&#8217;s go ahead and do that.<\/p>\n\n\n\n<p>Now, we&#8217;ll save it.<\/p>\n\n\n\n<p>********** Final Notes (08m 04.2s)<\/p>\n\n\n\n<p>Okay, let&#8217;s do one more.<\/p>\n\n\n\n<p>Now, notice that when saving multiple files with the same name, SignalScope will automatically start numbering them.<\/p>\n\n\n\n<p>Another thing to note here is that you can select just a portion of an audio file to analyze, and you can enable repeating playback for cases<\/p>\n\n\n\n<p>in which you would like to let the analysis run for a longer period of time.<\/p>\n\n\n\n<p>To end, here is the Polar Plot showing the directional nature of the gunshots at different frequencies.<\/p>\n\n\n\n<p>If you have any questions about how to get the most out of SignalScope, please visit us at <a href=\"http:\/\/FaberAcoustical.com\">FaberAcoustical.com<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>This video shows how to use the MultiTool in SignalScope X to analyze data in an audio file (WAV, AIF, or CAF) using SignalScope&#8217;s File Player and Octave Analyzer tools.<\/p>\n","protected":false},"author":3,"featured_media":2260,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,6,67],"tags":[33,210,28,213,212,99,98,36,30,180,211,22,136,209],"class_list":["post-2255","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tutorials-iphone","category-tutorials-mac","category-video","tag-acoustics","tag-analyze","tag-audio","tag-directivity","tag-gunshot","tag-ipad","tag-iphone","tag-mac-2","tag-measurement","tag-octave","tag-player","tag-signalscope","tag-top_post","tag-wav-file"],"_links":{"self":[{"href":"https:\/\/blog.faberacoustical.com\/wpblog\/wp-json\/wp\/v2\/posts\/2255","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.faberacoustical.com\/wpblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.faberacoustical.com\/wpblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.faberacoustical.com\/wpblog\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.faberacoustical.com\/wpblog\/wp-json\/wp\/v2\/comments?post=2255"}],"version-history":[{"count":4,"href":"https:\/\/blog.faberacoustical.com\/wpblog\/wp-json\/wp\/v2\/posts\/2255\/revisions"}],"predecessor-version":[{"id":2259,"href":"https:\/\/blog.faberacoustical.com\/wpblog\/wp-json\/wp\/v2\/posts\/2255\/revisions\/2259"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.faberacoustical.com\/wpblog\/wp-json\/wp\/v2\/media\/2260"}],"wp:attachment":[{"href":"https:\/\/blog.faberacoustical.com\/wpblog\/wp-json\/wp\/v2\/media?parent=2255"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.faberacoustical.com\/wpblog\/wp-json\/wp\/v2\/categories?post=2255"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.faberacoustical.com\/wpblog\/wp-json\/wp\/v2\/tags?post=2255"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}