• Caller's need
• Cell phone's lack
• Dead phone's lack
• Indication of service availability
• It may follow a click
• It's a mix of 350 Hz and 440 Hz in the United States
• It's okay to call now signal
• Landline feature
• Landline signal
• One thing land-lines have that cellphones lack
• Open line indicator
• Open-line signal
• Phone drone
• Phone sound
• Prerequisite of effective button-pushing
• Ready signal of a kind
• Ready signal of a sort
• Receiver sound
• Sign of a hang-up?
• Sign of a working phone
• Signal to place a call
• Sound after a hang-up
• Sound from a receiver
• Sound that stops at the cradle
Тоновий сигнал готовності (лінії)