For this you need to locate all faucets hose (hose faucets are where you connect pipes hoses If you do not you know). Usually an average house has a hose faucet in front and another in the back, but be sure to find all the taps you have and listen carefully.
After you have found them, take a screwdriver, preferably one long enough for you to have room to work. Then insert the metal tip of the screwdriver into the metal part of the hose tap. Place the knuckle of your thumb on top of the screwdriver, then place the knuckles of your other hand on the side of your head, just over your ear. The sound will travel directly to your eardrum. The idea is to turn the screwdriver into a stethoscope. This trick also works for most valves.
Listen carefully to any sound coming out of the faucet for hoses. If you hear something, do not forget where the noise is (you may want to mark the place with chalk), and then go to the next tap. If the sound becomes louder on one of the taps, then the leak is closer to that unit. Write it down and call the plumber. Giving this valuable information to the plumber will save you a lot of time in finding the leak, which in turn will save you money.
If you have checked all the faucets and still cannot find any sound, enter the house and repeat the same procedure with the screwdriver in the accessories such as sink faucets, shower valves, washing machine and water heater (be careful do not burn when working near the water heater). If you’re still not sure, you better contact the plumber.