nnels, testFrames, sampleRate);

        // Create a set of oscillators as the multi-channel source.
        let source = [];

        for (k = 0; k < nChannels; ++k) {
          source[k] = context.createOscillator();
          source[k].type = 'sawtooth';
          // The frequency of the oscillator is pretty arbitrary, but each
          // oscillator should have a different frequency.
          source[k].frequency.value = 100 + k * 100;
        }

        let merger = context.createChannelMerger(3);

  