Listen to the sound clip Auto Slot mk 2 ticket machine, child's fare of 3d inserted several times (London Transport green Country bus) from Bus Ticket Machines (London Transport) Soundboard:

Auto Slot mk 2 ticket machine, child's fare of 3d inserted several times (London Transport green Country bus)

This sound is from Bus Ticket Machines (London Transport) Soundboard

Bus Ticket Machines (London Transport) sound clips and sound effects, available to play and download.