I left out a few not revelant for the purposes here, such as loitering for the purposes of prostitution, loitering in a transportation facility, loitering while masked (disguised), or loitering near school grounds. If the people in question aren't doing any of the following, there is probably not much you can do, as merely "hanging out" and looking trashy is not a crime, but making excessive noise is a no-no. The only thing I can think of is to try and find out if you have a neighborhood association and give them a call or attend a meeting and see if this issue is being discussed. Find out who your City Council member is and drop them a line.
§ 240.35 Loitering.
A person is guilty of loitering when he:
Loiters or remains in a public place for the purpose of gambling
with cards, dice or other gambling paraphernalia; or
Loitering is a violation.
§ 240.36 Loitering in the first degree.
A person is guilty of loitering in the first degree when he loiters or
remains in any place with one or more persons for the purpose of
unlawfully using or possessing a controlled substance, as defined in
section 220.00 of this chapter.
Loitering in the first degree is a class B misdemeanor.
§ 240.10 Unlawful assembly.
A person is guilty of unlawful assembly when he assembles with four or
more other persons for the purpose of engaging or preparing to engage
with them in tumultuous and violent conduct likely to cause public
alarm, or when, being present at an assembly which either has or
develops such purpose, he remains there with intent to advance that
purpose.
Unlawful assembly is a class B misdemeanor.
§ 240.20 Disorderly conduct.
A person is guilty of disorderly conduct when, with intent to cause
public inconvenience, annoyance or alarm, or recklessly creating a risk
thereof:
1. He engages in fighting or in violent, tumultuous or threatening
behavior; or
2. He makes unreasonable noise; or
3. In a public place, he uses abusive or obscene language, or makes an
obscene gesture; or
4. Without lawful authority, he disturbs any lawful assembly or
meeting of persons; or
5. He obstructs vehicular or pedestrian traffic; or
6. He congregates with other persons in a public place and refuses to
comply with a lawful order of the police to disperse; or
7. He creates a hazardous or physically offensive condition by any act
which serves no legitimate purpose.
Disorderly conduct is a violation.
§ 240.26 Harassment in the second degree.
A person is guilty of harassment in the second degree when, with
intent to harass, annoy or alarm another person:
1. He or she strikes, shoves, kicks or otherwise subjects such other
person to physical contact, or attempts or threatens to do the same; or
2. He or she follows a person in or about a public place or places; or
3. He or she engages in a course of conduct or repeatedly commits acts
which alarm or seriously annoy such other person and which serve no
legitimate purpose.
Subdivisions two and three of this section shall not apply to
activities regulated by the national labor relations act, as amended,
the railway labor act, as amended, or the federal employment labor
management act, as amended.
Harassment in the second degree is a violation.
§ 240.40 Appearance in public under the influence of narcotics or a drug
other than alcohol.
A person is guilty of appearance in public under the influence of
narcotics or a drug other than alcohol when he appears in a public place
under the influence of narcotics or a drug other than alcohol to the
degree that he may endanger himself or other persons or property, or
annoy persons in his vicinity.
Appearance in public under the influence of narcotics or a drug other
than alcohol is a violation.
§ 240.45 Criminal nuisance in the second degree.
A person is guilty of criminal nuisance in the second degree when:
1. By conduct either unlawful in itself or unreasonable under all the
circumstances, he knowingly or recklessly creates or maintains a
condition which endangers the safety or health of a considerable number
of persons; or
2. He knowingly conducts or maintains any premises, place or resort
where persons gather for purposes of engaging in unlawful conduct.
Criminal nuisance in the second degree is a class B misdemeanor.
From New York City code (the above are Statewide laws):
§ 24-218 General prohibitions. (a) No person shall make, continue or
cause or permit to be made or continued any unreasonable noise.
(b) Unreasonable noise shall include but shall not be limited to
sound, attributable to any device, that exceeds the following prohibited
noise levels:
(1) Sound, other than impulsive sound, attributable to the source,
measured at a level of 7 dB(A) or more above the ambient sound level at or after 10:00 p.m. and before 7:00 a.m., as measured at any point within a receiving property or as measured at a distance of 15 feet or more from the source on a public right-of-way.
(2) Sound, other than impulsive sound, attributable to the source,
measured at a level of 10 dB(A) or more above the ambient sound level at or after 7:00 a.m. and before 10:00 p.m., as measured at any point within a receiving property or as measured at a distance of 15 feet or more from the source on a public right-of-way.
(3) Impulsive sound, attributable to the source, measured at a level
of 15 dB(A) or more above the ambient sound level, as measured at any point within a receiving property or as measured at a distance of 15 feet or more from the source on a public right-of-way. Impulsive sound levels shall be measured in the A-weighting network with the sound level meter set to fast response. The ambient sound level shall be taken in the A-weighting network with the sound level meter set to slow response.