t the source between frame boundaries
        let startFrame = 27.3;
        src.start(startFrame / context.sampleRate);

        context.startRendering()
            .then(audioBuffer => {
              let actualStartFrame = Math.ceil(startFrame);
              let audio = audioBuffer.getChannelData(0);

              should(
                  audio.slice(0, actualStartFrame),
                  `output[0:${actualStartFrame - 1}]`)
                  .beConstantValueOf(0);
              should(
            