Dear colleagues, We are pleased to invite you to the *4th Ultrasonic Vocalizations Conference*, taking place *online on November 20-21, 2025*. This event brings together researchers and practitioners exploring *ultrasonic vocalizations (USVs)* and their role in: • neuroscience and behavioral science, • acoustic communication across species, • technology and sound analysis, • creative approaches to studying communication. The program will feature: - *talks by international experts*, - *panel discussions and interactive Q&A sessions*, - *over twenty confirmed speakers and panelists* from neuroscience, biology, psychology, technology, and the arts. *Registration is now open and participation is free of charge.* More information and the registration link are available at: https://ultrasonicvocalizations.net/ https://www.facebook.com/UltrasonicVocalizationsNetwork/ We warmly invite you to join us for two days of interdisciplinary discussion and exchange. Best regards, *The 4th Ultrasonic Vocalizations Conference Organizing Committee* -- *Alicja K. Terelak, MSc* Laboratory of Spatial Memory, Nencki Institute of Experimental Biology, Polish Academy of Sciences Warsaw, 3 Pasteur Street, 02-093