🔍 Key Concepts

• Sound-powered telephone operation (no external power, voice energy only) • Function of a push-to-talk (PTT) button on communication devices • Difference between talking and listening circuits on shipboard phones

💭 Think About

• On most handsets with a push button, what changes when you press the button: the microphone, the receiver, or both? • If the phone must still be able to receive urgent calls at any time, would it make sense to have to hold a button to listen? Why or why not? • Think about how you would use this in an emergency: what would you be doing with the button when you are speaking versus when you are waiting for a reply?

✅ Before You Answer

• Verify which function is always available (listening or talking) without pressing any button. • Consider whether the push button is more likely to activate the transmitter (microphone) or the receiver (earpiece). • Check which option best matches the idea of a push-to-talk system often used in shipboard communications.