If you require police to attend to a noise complaint, telephone your local station or the Police Assistance Line on 131 444.

You will need to tell the operator the exact location where the noise is coming from and describe the type of noise. If you are disturbed by a particular incident like amplified music or excessive crowd noise, police can issue a warning or issue a noise abatement direction directing a person to stop making the offensive noise.

Offensive noise can be any noise that, by reason of its level, nature, character or quality, or the time at which it is made, or any other circumstances is harmful to (or is likely to be harmful to) or interferes unreasonably with the comfort of a person who is outside of the premises.  

If you are concerned about noise from a loud party, there are time restrictions on loud music

In NSW, there are restrictions on noise from musical instruments and sound systems which are commonly used at parties. Noise from music that can be heard in any habitable rooms of a neighbouring residence must cease during certain times: midnight to 8am on Friday, Saturday or any day preceding a public holiday and 10pm to 8am on any other day.

If you're the host of the party, there are a few things you can do to make sure that your partying doesn't disturb your neighbours.

Notify your neighbours in advance. Tell them about your party plans. Give them your contact details so that they can contact you directly (rather than the police) with any concerns. Having advance warning may reduce concerns on the night of your party.

Ask guests to be quiet when they leave.

Move indoors. As the evening gets later, move music and guests inside.

Be considerate with your sound system. Make sure your speakers are not facing towards a neighbour. Also think about turning down the bass as this is often what bothers neighbours.

A noise abatement direction may be issued at any time of the day or night and can remain in force for up to 28 days from the time it was issued. A person who fails to comply with it can be issued with an on-the-spot fine of $200 ($400 for a corporation). Noise abatement directions cannot be appealed against. The police and authorised officers of councils have powers that allow them to seize equipment used to make noise (e.g. a sound system in contravention of a noise abatement direction).

Details about noise control, dealing with noise (neighbourhood, barking dogs, intruder alarms, noise from vehicles, noise abatement orders can be obtained from the NSW EPA website:

https://www.epa.nsw.gov.au/your-environment/noise/neighbourhood-noise

The NSW Office of Environment & Heritage have information on the time restrictions

During these times, noise should not be heard in a habitable room in a neighbour's residence.

Power tools (Including Lawn Mowers, leaf blowers, edge cutters, chainsaws and shredders): 8pm to 8am on any Saturday, Sunday or public holiday; 8pm to 7am on any other day

Pumps and heat water pumps (incl. swimming pool and spa pumps): 8pm to 8am on any Saturday, Sunday or public holiday; 8pm to 7am on any other day

Music: Midnight to 8 am on Friday, Saturday or any day preceding a public holiday; 10pm to 8am on any other day

Air conditioner or water heater: 10pm to 8am on weekends and public holidays; 10pm to 7am on weekdays

Motor vehicles (except when entering or leaving residential premises): 8pm to 8am on weekends and public holidays; 8pm to 7am on any other day

Refrigeration unit fitted to motor vehicles: 8pm to 8am on weekends and public holidays; 8pm to 7am on any other day

Source: https://www.environment.nsw.gov.au/questions/times-residential-noise-restrictions