data(tico)
# a white palette to discard spectrogram plot
w <- colorRampPalette(c("white","white"))
# selection of tico song
tico2 <- cutw(tico, f=22050, from=0.5, to=0.9)
# spectro with contour related arguments
spectro(tico2, f=22050, ovlp=95, palette=w, cont=TRUE, colcont=temp.colors(8), contlevels=seq(-40,0,5), scale=FALSE)
title(main="A contour plot (iso-5dB levels)")