Automated voice guidance in devices such as water heaters and car navigation systems has become an indispensable part of daily life in Japan, yet few people might have stopped to consider why such services almost always use female?voices.

One common explanation points to the stereotype that women are naturally suited to supportive or caregiving roles.

¡°Your bath is ready,¡± announces a familiar female voice from the remote control of water heaters made by major manufacturer Rinnai.