2025_programme: Separation of Sperm Whales’ Clicks Using a Single Hydrophone

• Day: June 17, Tuesday
    Location / Time: A. TERPSIHORI at 08:50 - 09:10
• Last minutes changes: Cancelled
• Session: 08a. Bioacoustics and Soundscape
  Organiser(s): Jennifer Miksis-Olds, Giacomo Giorli
  Chairperson(s): Jennifer Miksis-Olds, Giacomo Giorli
• Lecture: Separation of Sperm Whales’ Clicks Using a Single Hydrophone
  Paper ID: 2111
  Author(s): Guy Gubnitsky, Roee Diamant
  Presenter: Guy Gubnitsky
  Abstract: Sperm whales use impulsive signals, echolocation clicks, to navigate and forage. Separating individual clicks from multiple whale sources is critical for understanding the whales' behavior, estimating population dynamics, and developing automated tools for species monitoring and conservation efforts. The task, however, is especially challenging in noisy marine environments or in areas where acoustic signals from multiple individuals overlap. We propose a novel three-stage algorithm for the separation of sperm whale clicks using a single sensor. The steps include separation of clicks in a short buffer, formation of click trains, and source attribution. We model temporal dependence between clicks from the same source using five features: click intensity, rhythm, slant delay (defined by the arrival time delay between the direct surface echo paths of the clicks) and temporal and spectral correlation through a first-order Markov chain. Click separation and click train formation are then performed using a MAP (Maximum a Posteriori) approach. The final step of source attribution is performed using a linear assignment that utilizes the distribution of the slant delay of the clicks. The evaluation of real-world at-sea data demonstrates high separation accuracy in a practical scenario with several whales clicking simultaneously and a low signal-to-noise ratio. The approach can be generalized to other hydroacoustic signals.
• Corresponding author: Mr Guy Gubnitsky
  Affiliation: University of Haifa
  Country: Israel