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Mellinger, D.K. 2004. A comparison of methods for detecting right
whale calls. Canad. Acoust. 32:55-65.
North Atlantic, North Pacific, and southern right whales all produce
the 'up' call, a frequency-modulated upsweep in the 50-200 Hz
range. This call is one of the most common sounds, and frequently the
most common sound, received from right whales, and as such is a useful
indicator of the presence of right whales for acoustic surveys. A data
set was prepared of 1857 calls and 6359 non-call sounds recorded from
North Atlantic right whales (Eubalaena glacialis) near Georgia and
Massachusetts. Two methods for the detection of the calls were
compared: spectrogram correlation and a neural network. Spectrogram
correlation parameters were chosen two ways, by manual choice using a
sample of 20 calls, and by an optimization procedure that used all
available calls. Neural network weights were trained via
backpropagation on 9/10 of the test data set. Performance was measured
separately for calls of different signal-to-noise ratio, as SNR
heavily influences the performance of any detector. Results showed
that the neural network performed best at this task, achieving an
error rate of less than 6%, and is thus the preferred detection method
here. Spectrogram correlation may be useful in situations in which a
large set of training data is not available, as manual training on a
small set of examples achieved an error rate (26%) that may be
acceptable for many applications.
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