As you may have noticed, above you will find words for "A filter of trapezoidal shape specified by four corner frequencies, f1 through f4. The filter rejects below f1 and above f4, is linear from f1 to f2 and from f3 to f4, and is flat from f2 to f3.". Hover the mouse over the word you'd like to know more about to view its definition. Click to find a better fitting word. Finally, thanks to ChatGPT, the overall results have been greatly improved.