3-tone major chord signal (simulation VI). The upper panel shows the oscillator frequency (i.e., fundamental frequency estimate) f_c of three PM-HLL instances as a function of time. Each instance targeted one of the tones by selecting the instance’s initial f_c to be a semitone above the target’s f₀, i.e., f₀ lies at the upper edge of the instance’s catch range. In the plot, each instance’s f_c time course was referenced to its target f₀, i.e., the target f₀ is plotted at 0 Hz. The PM-HLL instances converge within about 20 ms at an SNR of −2.2 dB for each tone. Strobe points are plotted separately for the different instances, with shorter bar lengths for higher tones. The middle panel shows the mean HNR per component, and the lower panel shows the non-normalized intensity spectrum of the first 30 ms of the signal (coarse curve) and of the complete signal (fine curve). The tones may not be derived from the 30-ms FFT data, because tonal components are not resolved. Note that the PM-HLL converged in 20 ms.