one_line_sound.rb

require 'sound'

Sound::Device.new {|d| d.play Sound::Data.new.sine_wave(440, 500, 1)}

# This is the short way that opens and closes the device automatically
# Here is the more verbose way:

device = Sound::Device.new("w")
format = Sound::Format.new(Sound::Format::PCM)
data = Sound::Data.new(format)
data.generate_sine_wave(440, 500, 1)
device.write(data)
device.flush
device.close