+ANNEX I NOISE INDICATORS

ANNEX I NOISE INDICATORS



ANNEX I

NOISE INDICATORS

referred to in Article 5

1.   Definition of the day-evening-night level Lden

The day-evening-night level Lden in decibels (dB) is defined by the following formula:[EUR-Lex]

in which:

— 
Lday is the A-weighted long-term average sound level as defined in ISO 1996-2: 1987, determined over all the day periods of a year,
— 
Levening is the A-weighted long-term average sound level as defined in ISO 1996-2: 1987, determined over all the evening periods of a year,
— 
Lnight is the A-weighted long-term average sound level as defined in ISO 1996-2: 1987, determined over all the night periods of a year;

in which:

— 
the day is 12 hours, the evening four hours and the night eight hours. The Member States may shorten the evening period by one or two hours and lengthen the day and/or the night period accordingly, provided that this choice is the same for all the sources and that they provide the Commission with information on any systematic difference from the default option,
— 
the start of the day (and consequently the start of the evening and the start of the night) shall be chosen by the Member State (that choice shall be the same for noise from all sources); the default values are 07.00 to 19.00, 19.00 to 23.00 and 23.00 to 07.00 local time,
— 
a year is a relevant year as regards the emission of sound and an average year as regards the meteorological circumstances;

and in which:

— 
the incident sound is considered, which means that no account is taken of the sound that is reflected at the façade of the dwelling under consideration (as a general rule, this implies a 3 dB correction in case of measurement).

The height of the Lden assessment point depends on the application:

— 
in the case of computation for the purpose of strategic noise mapping in relation to noise exposure in and near buildings, the assessment points must be 4,0 ± 0,2 m (3,8 to 4,2 m) above the ground and at the most exposed façade; for this purpose, the most exposed façade will be the external wall facing onto and nearest to the specific noise source; for other purposes other choices may be made,
— 
in the case of measurement for the purpose of strategic noise mapping in relation to noise exposure in and near buildings, other heights may be chosen, but they must never be less than 1,5 m above the ground, and results should be corrected in accordance with an equivalent height of 4 m,
— 
for other purposes such as acoustical planning and noise zoning other heights may be chosen, but they must never be less than 1,5 m above the ground, for example for:
— 
rural areas with one-storey houses,
— 
the design of local measures meant to reduce the noise impact on specific dwellings,
— 
the detailed noise mapping of a limited area, showing the noise exposure of individual dwellings.

2.   Definition of the night-time noise indicator

The night-time noise indicator Lnight is the A-weighted long-term average sound level as defined in ISO 1996-2: 1987, determined over all the night periods of a year;

in which:

— 
the night is eight hours as defined in paragraph 1,
— 
a year is a relevant year as regards the emission of sound and an average year as regards the meteorological circumstances, as defined in paragraph 1,
— 
the incident sound is considered, as laid down in paragraph 1,
— 
the assessment point is the same as for Lden.

3.   Supplementary noise indicators

In some cases, in addition to Lden and Lnight, and where appropriate Lday and Levening, it may be advantageous to use special noise indicators and related limit values. Some examples are given below:

— 
the noise source under consideration operates only for a small proportion of the time (for example, less than 20 % of the time over the total of the day periods in a year, the total of the evening periods in a year, or the total of the night periods in a year),
— 
the average number of noise events in one or more of the periods is very low (for example, less than one noise event an hour; a noise event could be defined as a noise that lasts less than five minutes; examples are the noise from a passing train or a passing aircraft),
— 
the low-frequency content of the noise is strong,
— 
LAmax, or SEL (sound exposure level) for night period protection in the case of noise peaks,
— 
extra protection at the weekend or a specific part of the year,
— 
extra protection of the day period,
— 
extra protection of the evening period,
— 
a combination of noises from different sources,
— 
quiet areas in open country,
— 
the noise contains strong tonal components,
— 
the noise has an impulsive character.

1. Pārskats

,

1.1 Atsauces

1.2 Identificētās prasības

1.3 Saistītie standarti

2. Identificētās prasības

Prasības

3. Saistītie standarti

Standarti