vol 
Get and set sound volume.
Install
$ npm install --save vol
Usage
var vol = require('vol');
vol.get(function (err, level) {
console.log(level);
});
vol.set(0.65, function (err) {
console.log('Changed volume to 65%');
});
vol.mute(function (err) {
console.log('Volume muted');
});
CLI
$ npm install --global vol
$ vol --help
Usage
$ vol (Interactive CLI)
$ vol <level>
$ vol mute
API
.get(callback)
Get volume level.
callback(err, level)
Type: function
level
Type: number
Current volume level.
.set(level, callback)
Set volume level.
level
Required
Type: number
A number between 0 and 1.
callback(err)
Type: function
Returns nothing but a possible exception.
License
MIT © Andreas Gillström