When editing a sound to post on the soundmap, you will need to trim the sound to just the portion you need, and you will need to adjust the sound levels to make them easily audible to users.
If you are creating a post about a reverberant space, it should have a spectrograph of the sound, along with information about sound decay (reverberation time, which is the amount of time it takes the sound to attenuate by a certain amount of decibels, usually 60 if possible). You may also wish to include a spectrograph in a post about a soundscape or wildlife sounds.
Audacity (available at http://www.audacityteam.org/ ) is a great free tool for editing. It can also show waveforms and spectrographs that look good on your computer screen, but it is not good at exporting those images as graphics files. Another free app, Sonic Visualizer, can do the latter very well but not the former. Neither will optimize the graph to show a certain drop in sound level.
Therefore I’ve created plugins for another app, Praat, another free app commonly used by linguists. Getting Praat ready to go and learning to use it is complicated, but the plugins make the last part of the process simple. I’m happy to help with this. You’ll need the balloon-pop function of the plugin for reverb. It also has a soundscape function in case you’d like to try it, but the soundmap doesn’t require spectrographs, so if you’re just doing a soundscape I recommend skipping this or trying Sonic Visualizer
Note: To keep the Media folder in the soundmap site manageable, please save all files with filenames based on location. If you record in Margaret Fowler garden, for example, save them as 2017-Feb-SCR-Fowler or something like that. The Praat plugins will do this automatically.
Praat instructions
- Download the plugins as a .zip file.
- Download Praat from http://www.fon.hum.uva.nl/praat/.
- Install simply by opening (double-clicking) the downloaded dmg (Mac) or zip (PC) and copying the file to your desktop or wherever else you want to put it. No need to formally install it or place it in an apps folder if you don’t want to.
- Open and close Praat once.
Besides confirming that the application will open, this creates a preference directory which you will need soon.
Mac
- Go to desktop, click Go > Go to Folder on the upper-hand Finder menu
- Copy and paste ~/library/into the “Go to Folder:” bar and hit Go
- Open the folder named “Preferences”, then the folder named “Praat Prefs”
- Go back to the plugin zip file and open it by double-clicking. Drag and move the plugin (plugin_soundmap_praat) folder, including all of its contents, into Praat Prefs.
Praat is ready to be used after this step
Windows / PC
- In the File Explorer window, navigate to (substitute your local user name for “username”): C:\Users\username\Praat
- Go back to the plugin zip file and open it by double-clicking. Paste the folder “plugin_soundmap_praat,” including all of its contents, into the “Praat” folder that you found in the previous step.
Praat is ready to be used after this step.
Continue for all computers
- Find the sound file you want to work with, right-click and Open With Praat
- Select the file on the Praat Objects window. For a balloon pop, hit the button Balloon-pop Step 1. Otherwise hit Soundscape Step 1.
- On the bottom left corner of the pop-up Edit window, several buttons labeled all, in, etc. help you zoom in and out. Hit all
Otherwise only the first 30 seconds of your sound will be displayed
- Click on a part of the graph where you want to add a tag for a sound event, then click on the circle that pops up on the events column
- Type in the name of the event and hit enter
Repeat the steps above for all desired sound events
- Move your cursor into the waveform or spectrograph, then click and drag to select the portion of the sound you want to use in your graph. (The selected part will change color.)
- In the Edit window, Go to File > Balloon-pop Step 2 or Soundscape Step 2 as appropriate.
- Select appropriate location names in the popup window and name the file and hit the save button. This will give you image and sound files with standardized filenames. You will upload the .png file to the soundmap.
