The masking effect is shown in each graph at various masker sound levels. Masking can also happen when a signal starts after a masker stops. A masked signal can be heard even though it is weaker than the masker. This reduces the effect of the masker by increasing the SNR. The masks have narrow eye slits to enable the masker to see without being seen. The frequency of the masker is kept constant. Combination tones are products of a signal and a masker. This refers to the case where a masker causes a threshold elevation. The festival saw the use of a theme for the first time - Masker (Mask).