peak filter

The filter curve of peak filters has a bell-shaped curve, which is why they are also called bell filters or Bell filters.

The frequency response of peak filters has a symmetrical curve around a center frequency. At the center frequency, the peak filter has the highest attenuation or gain. The center frequency can be varied, as can the attenuation curve as a function of the quality factor. In practice, peak filters are used in equalizers as presence filters to improve the formants.