Goats and sheep do indeed make sounds that are often transcribed as "bah" and "baa." While the exact sound can vary among individuals and breeds, these vocalizations are characteristic of these animals.
Sheep typically produce a sound referred to as "baa." It's a vocalization they use to communicate with other sheep or their lambs. The "baa" sound can have different variations and meanings depending on the context. For example, a ewe might "baa" to locate her lamb, or a lamb might "baa" to call for its mother. The sound can range from a soft and gentle "baa" to a more prolonged and loud call.
Goats, on the other hand, often produce a sound described as "bah" or "maa." Again, this vocalization can vary depending on the individual and the situation. Male goats, or bucks, may make a deep and throaty "bah" sound during mating season to establish dominance and attract females. Female goats, or does, may produce a higher-pitched and more melodic "maa" sound when calling their kids or communicating with other goats.
It's worth noting that the onomatopoeic representations of these sounds, such as "bah" and "baa," are an approximation of what humans perceive. The actual sounds produced by goats and sheep may not perfectly match these transcriptions, but they are commonly represented this way in popular culture, including nursery rhymes and children's songs.