Find occurences in string

occure.rb

a = 'Baloon . || woo,,ooddreeeed'
occurences = Hash.new(0)
array = a.gsub(/\W+/, '').split('')
array.each_with_index do |el, idx|
  break if array.size == idx + 1
  if el == array[idx + 1] && el != array[idx - 1]
    occurences[el] += 1
  end 
end

occurences.values.reduce(:+)