You can look at the MP3 chips of Guangzhou Jiuxin Electronics, including N9200, N920 1, N9 100, N9 102, which can be externally connected with flash memory, and the sound source can be updated or erased by connecting a computer through USB.
If you want a voice chip with built-in flash memory, you can look at NVF.
These flash memory capacities can be selected according to the needs of users.