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.