a Time and frequency resolution of the STFT for a short (top) and wide (bottom) window at three different frequencies. Temporal resolution is expressed in time (left) or in oscillation cycles at the target frequency (right). b Same as in a but for wavelets (CWT). Here, the number of cycles is fixed across the spectrum but the spanned temporal window decreases with frequency increase. c Superlets of order 2 (SLT). Time-frequency super-resolution is achieved by combining short, large-bandwidth wavelets, with longer, narrow-bandwidth wavelets.