Sonographic structure of isolation-induced ultrasonic calls of rat pups

Principles of Rat Communication: Quantitative Parameters of Ultrasonic Calls in Rats

“…Acoustic parameters in 10-17 day old Wistar pups differ by more than 65-70-times between minimal and maximal values (in single-call duration, sound-peak frequency, and bandwidth) (Brudzynski et al, 1999). Also, the call number and sonographic structure are equally variable (Elsner et al, 1990;Brudzynski et al, 1999). Pups appear not to utilize a single acoustic parameter coding the ''message's'' quantitative dimension but rather all parameters contribute to being found and attended to by the mother (locating function).…”

“…Pup ultrasonic calls are extremely variable in all acoustic parameters. Acoustic parameters in 10-17 day old Wistar pups differ by more than 65-70-times between minimal and maximal values (in single-call duration, sound-peak frequency, and bandwidth) (Brudzynski et al, 1999). Also, the call number and sonographic structure are equally variable (Elsner et al, 1990;Brudzynski et al, 1999).…”

“…Thus, in addition to lacking the grammatical and syntactic complexity of human speech, rat communication also lacks the lexical precision of human communication. Nevertheless, rats can respond reliably to vocal signals of conspecifics and can discern the semiotic content even though, their calls may not be acoustically identical (Brudzynski and Chiu, 1995;Brudzynski, 2001;Brudzynski et al 1999;Sales, 1991). This feature in animal's response is also observed for the vocalizations of other species and represents evidence for the existence of a recognizable sign function.…”

“…All acoustic features facilitating sound localization are present in the pups' isolation calls, and this corroborates the critical importance of the dam's attention and attendance for the pups' survival. Although, increasing duration and peak frequency of the calls with age contribute to quantitative coding, (Brudzynski, et al, 1999), the number of frequency sweeps appears to be a main localization factor. Successive deep sweeps of sound frequency, analogous to an ambulance siren, are produced by a majority of pups.…”

“…The total population of sonographically analyzed calls is n ¼ 1211 (78 pups) for 10-day old pups, and n ¼ 438 (71 pups) for 17-day old pups. The data originate from results contained in the study by Brudzynski, Kehoe and Callahan, (1999). narrow bandwidth of 1-6 kHz and long call duration of approximately 300-3400 ms (Barfield and Geyer, 1975;Brudzynski et al, 1993;Brudzynski and Ociepa, 1992;Brudzynski, 2001;Miczek et al, 1991;Sales, 1979).…”