Noise can be either non-stop or it may stop and start but either way, it becomes a nuisance when it starts to affect the comfort or quality of life of a reasonable person. What matters is that you feel that the noise is really having a negative effect on your comfort or quality of life and that any other reasonable person would respond to the noise in the same way.
To report noise nuisance contact the Noise Team on 020 8583 5555. If you are reporting noise nuisance between 10pm and 4am Friday or Saturday, contact the Weekend Noise Team on 020 8583 2222. You will need to provide your name, address and details of where the noise is coming from.
For more information on Noise Nuisance see Hounslow Council's Noise Nuisance page