As a general term, a sound command could be any computer command that has to do with sound. There are two possible references that are most likely. One is the command used when doing sound recording from the command line. The other is the HTML sound command.
The command line, also called the DOS prompt, when working in a Microsoft® environment, or the shell, when working in a Mac, Linux, or Unix environment, is a user interface that is separate from the graphical user interface (GUI) and can be used to give commands to the operating system. The command for sound recording has six standard parts, including the initial command, the mono/stereo setting, the sampling rate, the threading priority, the recording time limit, and the name for the output file, which also identifies the file format. Since some of these elements are set by default, the simplest example would read:
$ sound-recorder -P recording.wav
It is in HTML (HyperText Markup Language) 4, that there is the item most closely resembling a sound command. Different browsers have different syntax requirements, and for the Mosaic browser to play a background sound, the HTML element <SOUND> is used. <EMBED> was used with Navigator, but is now obsolete. <BGSOUND> is the standard HTML 4 alternative, and those who used <EMBED> were advised to add <BGSOUND>, the standard method used for Internet Explorer®.
Creating a sound command with any of these three methods is similar. All three tags — <SOUND>, <EMBED>, and <BGSOUND> — are followed by command parameters. Three are standard: SRC to set the path; LOOP to allow replaying of the sound a certain number of times or endlessly until the page is closed; and DELAY to institute a delay in seconds before playing an inline sound. Either an absolute or a relative URL can be used for the path. With an infinite loop, each of the three tags playing a file called birdsong.wav would appear like this:
<SOUND SRC="birdsong.wav" LOOP=infinite>
<EMBED SRC="birdsong.wav" LOOP=infinite>
<BGSOUND SRC="birdsong.wav" LOOP=infinite>
HTML 5 introduces a new approach for dealing with a sound command. The tag is <audio> and it is used as a toggle tag, meaning there is a start and end tag. Attributes related to this tag include autoplay, which plays the file as soon as it can; controls, which displays audio playback controls; preload, which loads the sound file when the page is loaded; and src, which defines the audio file’s URL.