It can be embarrassing if your phone rings when you’re in a meeting – even on silent, the phone’s vibration could still cause a disturbance.
To immediately silence your phone, just tap either of the Volume buttons or the On/Off button on the top of your iPhone.
Even if you silence a call, it will still seem like the phone is ringing to the caller, but your iPhone will now be silent and stop vibrating.
Send to Voicemail
Send an incoming call directly to voicemail by pressing the On/Off button on the right side of the phone twice (or on the top of the phone if you are using an iPhone 5S or below.) If using the iPhone headphones, the same thing will happen if you press the central button twice on the headphone control.