 testFrames = testDurationSec * sampleRate;

      let audit = Audit.createTaskRunner();

      audit.define('coefficient-normalization', (task, should) => {
        // Test that the feedback coefficients are normalized.  Do this be
        // creating two IIRFilterNodes.  One has normalized coefficients, and
        // one doesn't.  Compute the difference and make sure they're the same.
        let context = new OfflineAudioContext(2, testFrames, sampleRate);

        // Use a simple impulse as the source.