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Fig. 2 | BMC Research Notes

Fig. 2

From: Nocturnal “humming” vocalizations: adding a piece to the puzzle of giraffe vocal communication

Fig. 2

Narrow-band spectrogram and waveform of an acoustic signal within the infrasonic range. Example of an acoustic signal recorded at Berlin Tierpark proving that the used Song Meter SM2+ (Wildlife Acoustics Inc.) for this study is capable of recording frequencies below 20 Hz. Dashed white line and black arrows indicate a detected signal at an average of 14.08 Hz. The spectrogram was generated in Praat 5.4.01 using the following settings: Gaussian window shape; frequency steps: 1000; time steps: 250; frequency range: 0–10 kHz; window lengths: 0.4 Hz; dynamic range: 40 dB

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