Voice message
Recorded audio message in chat. WhatsApp + Telegram popularized it ("hold mic button to record"). Standard in Latin America and the Middle East — in Sweden/USA still has social friction ("why not just text?").
Compression: Opus 8-24 kbps typical — 1 minute = 100-200 KB. WhatsApp added transcription in 2024 (locally on the phone, privacy). Telegram has had transcription since 2021 (Premium feature). Threema, Signal, iMessage also support it. Social dynamic: voice messages feel intimate/personal vs text — also more confusing since they can't be Ctrl+F'd. Speed control 1.5x/2x is default in every app now. Anti-pattern: 8 minutes of unstructured ramble — makes the recipient angry.