[Functional harmony of the sonar clicks and whistles in the acoustic emissions of the Amazonian dolphin Sotalis fluviatilis Gervais and Deville].

By analyzing acoustic signals recorded from Sotalia in the Amazon River, its appears that phonation system use the same mechanism to produce click and monochromatic whistling, with a regular evolution between them.

[Shape acoustical recognition and characteristics of sonar signals by the dolphin T. truncatus].

During the shape acoustical recognition process, the signal processing reveals two phases in the T. truncatus sonar emission. In the course of the first phase, the wide-band signals are invariant, during the second phase, near the end of the approach, their temporal and spectral characteristics change along with the shape of the objects to identify.