A tone generator is a great tool for troubleshooting that features single or multi-tone signals. It produces sounds artificially, by converting electrical signals into sounds. Depending on your application, the tone generator can suit to your requirements with varying levels of sound output from different models. Tone generators can be accompanied with probes that can easily be traced back to the tone generator if cables are in a wall, for example. Powered by a battery, a tone generator allows you to easily carry and work on hard to reach subjects.
It's a versatile device that can be used for several applications, such as testing voltages, diagnosing faults in wire shielding and tuning musical instruments.