Real-time Recognition of Whale Calls using SoundID

Real-time Recognition of Whale Calls using SoundID Neil J Boucher, SoundID. AustraliaMichihiro Jinnai, Nagoya Womens University. Japan

SoundID www.soundid.netFounded 2002Engineers specialising in sound recognitionAim to produce human expert and better quality recognitionDesigned to run in real-time Designed to handle terabytes of data with easeHave our own patented methods

Who Are We?SoundID Mk I in glorious 1-d!

1-d Recognition Results monitoring a Dawn Chorus over 70 minutes

The 1-d method works well for most bird calls as just shown. Frogs and bats also easy.Whales are harder because the 1/f noise and other background noises smear the 1-d image.Worse still, most of the whale noises are in-band.Birds are Easy, Whales are Hard2-d Depiction of Same Call

Two Methods Compared

The Bottom of the Coke Bottle or FFT-like View of the Same Call at Frame-Width 513 Points

Euclidean Distance is the simple straight line (first order) distance between two points.Geometric Distance (measured in angular degrees) is the angle between two vectors that we use to describe the difference in shape. It is a fourth order measure, vaguely related to the skew of a standard distribution.Geometric DistanceAs a measure of similarity we can use the GD between two n-dimensional shapes to measure their similarity. Two identical shapes have a GD = zero Two totally dissimilar shapes have a GD of 90 degrees.The spectra of two sounds that sound similar to the human ear can have a GD in the range 0 to about 6 degrees.The Measure of Geometric DistanceOnce we have a library of reference sounds we can compare that library with the detected target sound. Each sound in the library is compared in turn with the target and the one with the lowest GD is declared the closest match.Then, if the lowest GD is small enough to be declared a match (typically GD