require 'audio/sndfile'

  Audio::Soundfile.open('chunky_bacon.wav') do |sf|
    sound = sf.readf_float(sf.frames)

    puts "Maximum amplitude: #{sound.abs.max}"

    sound.each_frame do |frame|
    # something cool
    end
  end

ruby/audio provides a convenience wrapper around NArray that will make all your friends jealous; but what will really make their heads explode is that you have ruby-way access to libsndfile [2]. Use with caution.

1. hans.fugal.net/src/ruby-audio/
2. www.mega-nerd.com/libsndfile/