code: function ramp(param, fromValue, toValue, duration, linear) {
      if (context.isFake) {
          return;
      }
  
      param.setValueAtTime(fromValue, context.currentTime);
  
      if (linear) {
          param.linearRampToValueAtTime(toValue, context.currentTime + duration);
      } else {
          param.exponentialRampToValueAtTime(toValue, context.currentTime + duration);
      }
  }
docs: /*
  ramp audio param