Toilets are meant to be predictable appliances. They should always flush when you press the lever, and they should make a familiar whooshing noise as the water exits and refills in the tank. If you hear a strange, foghorn like noise emanating from your toilet, it typically signifies that there is a problem with the appliance.
The foghorn noise is most commonly associated with older model toilets with a metal ballcock style fill valve design. The sounds resonate from a loose washer in the ballcock assembly and can be very annoying for homeowners. In most cases you should contact a plumber in NYC to fix the issue.
In order to fix the noise, a plumber in NYC will have to replace the ballcock assembly. To do so, the plumber will remove the lift ball, armature, and the top flush valve from the tank. Then they will replace the worn out washer at the bottom of the valve and reassemble the mechanism.
It is not recommended to attempt to fix this issue without professional assistance. If you try to fix the toilet and fail, you may cause more significant damage to the appliance. If you are experienced with solving this problem, you should contact a plumber in NYC for more assistance.