Example: linear_gammachirp (hears)¶
Example of the use of the class
in the library. It implements a filterbank of FIR gammatone filters with linear
frequency sweeps as described in Wagner et al. 2009, “Auditory responses in the
barn owl’s nucleus laminaris to clicks: impulse response and signal analysis of
neurophonic potential”, J. Neurophysiol. In this example, a white noise is
filtered by a gammachirp filterbank and the resulting cochleogram is plotted.
The different impulse responses are also plotted.
from brian import * from brian.hears import * sound = whitenoise(100*ms).ramp() sound.level = 50*dB nbr_center_frequencies = 10 #number of frequency channels in the filterbank #center frequencies with a spacing following an ERB scale center_frequencies = erbspace(100*Hz, 1000*Hz, nbr_center_frequencies) c = 0.0 #glide slope time_constant = linspace(3, 0.3, nbr_center_frequencies)*ms gamma_chirp = LinearGammachirp(sound, center_frequencies, time_constant, c) gamma_chirp_mon = gamma_chirp.process() figure() imshow(gamma_chirp_mon.T, aspect='auto') figure() plot(gamma_chirp.impulse_response.T) show()