def click(duration, peak=None, samplerate=None, nchannels=1):
'''
Returns a click of the given duration.
If ``peak`` is not specified, the amplitude will be 1, otherwise
``peak`` refers to the peak dB SPL of the click, according to the
formula ``28e-6*10**(peak/20.)``.
'''
samplerate = get_samplerate(samplerate)
duration = get_duration(duration,samplerate)
if peak is not None:
if not isinstance(peak, dB_type):
raise dB_error('Peak must be given in dB')
amplitude = 28e-6*10**(float(peak)/20.)
else:
amplitude = 1
x = amplitude*ones((duration,nchannels))
return Sound(x, samplerate)
def set_level(self, level):
'''
Sets level in dB SPL (RMS) assuming array is in Pascals. ``level``
should be a value in dB, or a tuple of levels, one for each channel.
'''
rms_dB = self.get_level()
if self.nchannels>1:
level = array(level)
if level.size==1:
level = level.repeat(self.nchannels)
level = reshape(level, (1, self.nchannels))
rms_dB = reshape(rms_dB, (1, self.nchannels))
else:
if not isinstance(level, dB_type):
raise dB_error('Must specify level in dB')
rms_dB = float(rms_dB)
level = float(level)
gain = 10**((level-rms_dB)/20.)
self *= gain
