require 'rubygems'

class Player
  @@sound_path = ''
  @@sound_app = 'mpg321'
  @@process_devnull = '> /dev/null 2>&1'
  @@process_bg = '&'
  
  def self.sound_path=(value)
    @@sound_path = value
  end

  def self.sound_app=(value)
    @@sound_app = value
  end
                                  
  def self.process_devnull=(value)
    @@process_devnull = value
  end

  def self.process_bg=(value)
    @@process_bg = value
  end
  
  def self.play(file)
    cmd = "#{@@sound_app} #{@@sound_path + file} #{@@process_devnull} #{@@process_bg}"
    system cmd
  end
end

files = Dir.glob(File.join("/home/buildmaster/Desktop/sounds/error", "*.mp3"))
Player.play(files[rand(files.size)])

Play a file using ruby

Ruby