], k, 0, M) - sum(fb[k]*y[n-k], k, 1, N)
      //
      function iirFilter(input, feedforward, feedback) {
        // For simplicity, create an x buffer that contains the input, and a y
        // buffer that contains the output.  Both of these buffers have an
        // initial work space to implement the initial memory of the filter.
        let workSize = Math.max(feedforward.length, feedback.length);
        let x = new Float32Array(input.length + workSize);

        // Float64 because we want to match 