See: Headphone Jack (3.5mm) 2.5mm connectors are still common for TTY devices for the hearing impaired. Therefore most modern phones require a 3.5mm-to-2.5mm adaptor in order to connect to a TTY ...

Dependent on the number of connector rings, headphones can also include a microphone. The current trend is for high-end smartphone flagships to exclude the 3.5mm jack, with headphone support being ...

The final death knell to analog audio began with the iPhone 7 when Apple eliminated the 3.5mm earphones jack, a standard since the 1950s (see mini-phone connector). THIS DEFINITION IS FOR PERSONAL ...