unity – How do I stop gyroscope-controlled camera from jittering when holding phone still?

I have here a simplified version of my gyro-controlled camera with a sensitivity modification (a side effect of increasing sensitivity is that the jitteriness is exacerbated).

public class GyroControl : MonoBehaviour{

private Transform _rawGyroRotation;
Vector3 gyroAdjust;
(SerializeField) private float _smoothing = 0.1f;

void Start()
{
    Input.gyro.enabled = true;
    Application.targetFrameRate = 60;

    _rawGyroRotation = new GameObject("GyroRaw").transform;
    _rawGyroRotation.position = transform.position;
    _rawGyroRotation.rotation = transform.rotation;

}

private void Update()
{
    _rawGyroRotation.rotation = Input.gyro.attitude;

    gyroAdjust = _rawGyroRotation.rotation.eulerAngles * 2; //increase rotation sensitivity
    transform.rotation = Quaternion.Euler(gyroAdjust);

    transform.rotation = Quaternion.Slerp(transform.rotation, _rawGyroRotation.rotation, _smoothing);

}}

When in motion, the jittering isn’t noticeable. But when you hold the phone still, there’s what I assume to be just analogue noise that causes jittering. I would really appreciate any help or advice on how to add a filter or something to reduce the jittering for this kind of controller.

Thanks.