Tellstone

"Hold the stone in your palm with your thumb on the inscribed rune. Speak your message and release, the next time the rune is pressed, it will replay your message to the recipient"

— The Tellstone Instruction

The Message of the Many

Throughout the Eight Lands, there are many ways people send messages to those that need to receive them, many use paper and parchment, but for those who desire to hear the voice of the sender, tellstones are the best way to do so. Much like letters, it's considered rude to press a tellstone that was not yours to receive.
The creation of a tellstone isn't a difficult process, a simple magic that can be cast on any stone, though the larger the stone the larger the message that can be stored.
Pebbles and other small rocks can generally contain about fifty words, more or less what is needed for simple exchanges. Boulders can hold an entire book worth of speech, best for public areas and repeated messages.

The Spell for Speech

Marked on a stone, one must simply place the spiraling rune for speech. Multiple spirals can be placed on stones, though the more that are placed the weaker the stone becomes. If five spirals were placed on a pebble, it would crumble if crushed in a hand. If five spirals were placed on a boulder, it would do almost nothing.
While the rune for speech can be placed on any stone, the integrity of the stone means that there are some that are unwise to have it placed upon. Stones that are smaller than a copper standard are generally unfit for use as a tellstone.

Tellstone by Theiket (via MidJourney)