The objective of this study was the acoustic analysis of vocalizations of domestic dogs when they want to play with humans. Using a digital camcorder and microphone, we recorded and acoustically analyzed the vocalizations of six 7-month-old dogs (beagle) when they wanted to play with humans. The vocalizations were classified into five types, namely, barking (type Ⅰ, type Ⅱ), whining (type Ⅰ, type Ⅱ), and howling, based on the shapes of waveforms and spectrograms. There was a significant difference in the fundamental frequency (p<0.01), intensity (p<0.0001), 1st formant (p<0.001), 2nd formant (p<0.0001), 3rd formant (p<0.001), and 4th formant (p<0.05) among the vocalizations, whereas the duration was not different (p<0.05). Whining type I showed high values in the fundamental frequency and 3rd formant, while whining type II showed high values in the fundamental frequency and 1st, 2nd, and 4th formant. Further, bark types I and II showed high intensity values, with bark type II having a high value in the 1st formant. Finally, whining showed high values in the 4th formant only and significantly lower values in the 1st and 2nd formants than other vocalizations. Domestic dogs mainly exhibited barking and whining with differences in characteristics of fundamental frequency, intensity, and formant dispersion when they wanted to play with humans during the experiment. Accordingly, we suggest that vocalization could be a useful method for identifying dogs’ intentions or emotional state in a non-invasive manner.

The objective of this study was to comparatively analyze the vocalizations of farrowing sows and their piglets in a welfare certified farm and a conventional farm as they are useful parameters for animal welfare assessment. The conventional farm using the gestation stall, farrowing crate and nursery, grower‐finisher pigs were accommodated in small pens. On the other hand, in the welfare certified farm using the group feeding gestation sows, which allows them to turn around in the furrowing pens, unlike in the crates and nursery, grower‐finisher pigs were accommodated in large pens. Vocalization of farrowing sows and their piglets were recoded and acoustic parameters were analyzed. Eight vocalizations―screaming, fighting, playing, suckling competition, suckling, piglet call, frightened, and space competition―were recoded in the farrowing crate and classified; 4 ordinary and 4 non‐ordinary vocalizations were identified. However, frightened and space competition vocalizations were not detected in the farrowing pen. Screaming, fighting, playing, suckling competition, and suckling vocalizations were significantly (p<0.01) different in pitch, intensity and duration between the farrowing pen and the farrowing crate. Piglet call vocalization did not differ between the farrowing facilities. These findings will aid us in using the differences in vocalizations, under different conditions, as parameters of animal welfare assessment.

문둥이박쥐(Eptesicus serotinus)의 생후 발성발달 특징을 파악하기 위하여 임신한 암컷 3개체로부터 총 4개체의 새끼 박쥐를 확보하여 발성변화를 분석하였다. 녹음 및 분석은 생후 1일부터 40일까지 수행하였으며, 펄스 지속시간 (PD), 펄스 간격(PI), 최고 주파수(PF), 시작 주파수(FMAX), 종료 주파수(FMIN), 대역폭(BW)에 대하여 측정하였다. 새끼 박쥐는 생후 초기에 가장 다양한 패턴의 음성을 발산하였으며, 연령이 증가함에 따라서 점차 어미와 유사해졌다. PD와 PI는 연령이 증가할수록 감소하였으며, 반면 PF, FMAX, FMIN, BW는 증가하였다. PF, FMAX, FMIN, BW는 생후 10일에서 20일 사이에 가장 큰 변화가 확인되었으며, PD는 생후 30일에서 40일 사이에 가장 큰 변화가 확인되었다. 따라서 진동수의 발성과 관련이 있는 발성근육의 수축 능력은 생후 20일경 가장 발달하게 되며, 발성시간과 관련된 발성근육의 이완 능력은 생후 30일에서 40일 사이에 가장 발달하는 것으로 판단된다. 본 연구에 이용된 새끼 개체들은 생후 40일차에도 비행이 확인되지 않았으나 발성음은 어미와 유사하게 나타났다. 따라서 이러한 결과는 새끼 박쥐의 발성 발달은 비행행동 또는 비행과 관련된 근육의 발달을 필수적으로 동반하는 것은 아니라는 것을 보여주는 결과라 판단된다.