emission.sound_power_plant

Sound power levels of multisource industrial plants for the evaluation of sound pressure levels in the environment: ISO 8297:1994, engineering method (grade 2).

A petrochemical complex, a quarry or a crushing plant is too large for any enveloping surface of ISO 3744, and too full of sources for any one of them to be measured alone. ISO 8297 treats the whole plant as one source. A closed path, the measurement contour, is drawn round the plant area on the plot plan; microphones stand on it at equal spacing, raised to a height that grows with the area the contour encloses, and point horizontally at the plant; the octave-band levels they read are averaged, and a few corrections turn the average into the sound power the plant radiates towards its neighbours, the number a prediction model needs at a distance of at least 1,5 times the largest dimension of the plant area (clause 0.2 a).

The contour (clause 9.1.1) has three requirements. The average of the distances $d_i$ from each position to the nearest point of the plant perimeter (9.1.2.2),

shall exceed $0,05\sqrt{S_{\mathrm{p}}}$ or 5 m, whichever is the greater, and shall not exceed $0,5\sqrt{S_{\mathrm{p}}}$ or 35 m, whichever is the lesser, $S_{\mathrm{p}}$ being the plant area; the plant area shall be seen from any point of the contour inside an aspect angle of at most 180°; and adjacent positions shall be at most $2\bar{d}$ apart. The microphone height (9.3) is

with $S_{\mathrm{m}}$ the area the contour encloses and $H$ the characteristic height of the plant, the mean height of its $n$ sources (9.2 c), $H=\frac{1}{n}{\sum }_k{h}_k$.

Clause 10 then computes, band by band, the energy average of the levels $L_{pi}$ at the $N$ positions (10.1),

replaces any level more than 5 dB above that average by $\overline{L_p}+5$ dB and averages again into $\overline{L_p^{\ast }}$ when a contour further out is not practicable (10.2, 10.3), and adds four terms (10.4 to 10.8):

with $l$ the length of the contour, $S_0=1$ m², $\theta$ the angle at which a directional microphone has lost 3 dB ($\Delta L_{\mathrm{M}}=0$ for an omnidirectional one) and $\alpha$ the attenuation coefficient of the air. The area term is the measurement surface of ISO 3744: for a circular contour round a point source on the ground, $2S_{\mathrm{m}}$ is the hemisphere $2\pi r^2$ over it and $hl$ the band of wall of height $h$ round it. The proximity term has no factor 10: NOTE 11 says it lies between −0,9 dB and −1,9 dB when 9.1 is met, and $\lg (0,5/4)=-0,903$ and $\lg (0,05/4)=-1,903$ are its two ends. The A-weighted level of 10.9 is $L_{W\mathrm{A}}=10\lg {\sum }_{j}10^{0,1(L_{Wj}+C_j)}$ dB, with the octave-band $C_j$ of ISO 3744:2010 Annex E that every other sound power method of this library uses.

The air absorption. Table 3 prints $\alpha$ per octave band at 15 °C and 70 %, “taken from ISO 3891”, and asks for the values at the measured temperature and humidity when the weather differs markedly. With no weather given, plant_air_absorption_db_per_m returns Table 3 as printed; with a temperature and a humidity it evaluates the attenuation coefficient of ISO 3891:1978 Annex A (SAE ARP 866A) at the one-third-octave band centred on each octave, through the transcription phonometry.aircraft.atmospheric_absorption.arp866a_attenuation that the ECAC Doc 29 Appendix D implementation reads; there is no second copy of it here. ISO 3891 gives no evaluation frequency below 50 Hz, so the 31,5 Hz band keeps the 0 of Table 3 in any weather. At 15 °C and 70 % the formula agrees with Table 3 to its printed digit at 63 Hz and from 250 Hz to 2 kHz, and not at 125 Hz (0,000 59 dB/m against 0), 4 kHz (0,025 05 against 0,026) or 8 kHz (0,061 against 0,046): ISO 3891 Table 9 prints 0,1, 2,5 and 6,1 dB/100 m in those bands at those conditions, and ISO 8297 does not say how it drew its octave values from the one-third-octave data of ISO 3891, so Table 3 is kept as printed and the difference is recorded, not corrected. The difference reaches the sound power through $\Delta L_{\alpha }=0,5\alpha \sqrt{S_{\mathrm{m}}}$: passing 15 °C and 70 % gives $0,0074\sqrt{S_{\mathrm{m}}}$ dB more at 8 kHz than omitting the weather, 1,4 dB for a measurement area of 36 800 m². The weather is therefore for the case 10.7 names, a weather that differs markedly from 15 °C and 70 %; at or near those conditions Table 3 is the reading the standard gives.

What is judged and what is computed. plant_measurement_contour lays the positions on a contour given as a polygon round the plant polygon and measures everything 9.1 and 9.2 ask for; plant_sound_power runs clause 10 on the levels read there; check_plant_measurement holds the arrangement and the readings against the requirements of clauses 1.2, 6, 7.1, 9.1, 9.3, 9.5 and 10.2 and returns one verdict. Table 2 corrects the levels for background noise and Table 1 states the uncertainty of the method, which depends on $\bar{d}/\sqrt{S_{\mathrm{p}}}$ alone. Clause 0.2 b) uses the method to find the contribution of particular parts of a plant, and partial_plant_contributions combines the sound power of parts measured on their own contours into the whole and each part’s share of it.

Source: ISO 8297:1994, read in the identical British adoption BS ISO 8297:1994 (clauses 0 to 12, Tables 1 to 3, Figure 1).

Auto-generated from the source docstrings by scripts/generate_api_docs.py (make api-docs). Do not edit by hand.

check_plant_measurement(
    contour: PlantMeasurementContour,
    sound_power: PlantSoundPowerResult | None = None,
    *,
    measurement_time_s: float | ArrayLike | None = None,
    leq_range_db: float | ArrayLike | None = None,
) -> PlantMeasurementCheck

May clause 10 be applied to this measurement? ISO 8297 1.2, 6, 7.1, 9 and 10.2.

From the contour alone: the largest dimension of the plant area between 16 m and approximately 320 m (1.2); the average measurement distance inside the window of 9.1.1 a); the plant area seen from every point of the contour inside 180° (9.1.1 b); adjacent positions at most $2\bar{d}$ apart (9.1.1 c); no more than 10 % of the positions omitted (9.1.2.4); and the microphone at least 5 m high (9.3). With the determination as well: the directional microphone’s 3 dB angle above 30° in every band (7.1), the background at least 6 dB below every level (6 b), and the seven octave bands from 63 Hz to 4 kHz measured (9.5.1 a). With the measurement times: at least 1 min at each position (9.5.1). With the range of the integrated readings: an $L_{\mathrm{eq},T}$ that “does not fluctuate by more than ± 0,5 dB” at each position (9.5.3), a range of at most 1 dB.

Four rows are advisory: the standard lets them go unmet provided the report says so, so they do not decide PlantMeasurementCheck.passes. The first is the height of 9.3 itself. 9.3 prescribes a height, not a lower bound, so the row holds when the microphones stand at $H+0,025\sqrt{S_{\mathrm{m}}}$ (or 5 m) to within the ±5 % to which 9.2 reads $H$ and $S_{\mathrm{m}}$ off the plan, and a microphone lower (placed “as high as possible above the minimum height of 5 m” where the height cannot be reached) or higher than that is listed in PlantMeasurementCheck.deviations. The others are the background “preferably more than 10 dB” below (6 b), a level more than 5 dB above the contour average, which 10.2 answers with a new contour or with steps 2 and 3, and the upper end of 1.2, which the standard gives as approximate.

The background margin, the level above the contour average and the range of the integrated reading are settled to nine decimals before they meet their limits, so a difference of decimal readings is judged as the decimal it is: a background 64,4 - 54,4 dB below, 10,000 000 000 000 007 in binary, is the 10 dB that 6 b) does not prefer.

Some printed numbers are left to the measurement team and not judged here, by choice rather than because they cannot be computed: the ±5 % and ±30 % to which 9.2 and 9.1.1 a) ask the plan to be read, the calibration intervals of 7.3, and the reflecting surfaces and the wind of clause 6 a) and c), which the standard states without a number.

Parameters

Returns: A PlantMeasurementCheck.

Raises

partial_plant_contributions(
    parts: Sequence[PlantSoundPowerResult],
    *,
    names: Sequence[str] | None = None,
) -> PartialPlantContributions

Put together the parts of a plant measured on their own contours (0.2 b).

ISO 8297 is written for a whole plant, and 0.2 b) and c) also use it on particular parts of an industrial area, to find each part’s contribution and to compare component installations. The parts, each measured round its own contour and not overlapping, radiate incoherently, so the power of the whole is the energy sum of theirs band by band, and each part’s contribution is its level less that sum. NOTE 2 is the caveat: the sound power of a plant measured round one contour may differ from the sum of the powers of its sources, so this sum is not the same determination as the whole plant measured at once. Sources raised well above the plant (clause 11) are determined by other standards and reported beside the plant (item m) of clause 12); they are not summed in here.

Parameters

Returns: A PartialPlantContributions.

Raises

PartialPlantContributions(
    names: tuple[str, ...],
    frequencies_hz: NDArray[np.float64],
    part_levels_db: NDArray[np.float64],
)

The sound power of a plant put together from parts measured on their own contours, and each part’s share of it (0.2 b, c).

Attributes

property

Each part’s $L_{W\mathrm{A}}$ less the total, in decibels.

property

$L_{W\mathrm{A}}$ of each part over the bands of 10.9, in dB re 1 pW.

property

$L_{W\mathrm{A}}$ of the parts together, in dB re 1 pW.

property

Each part’s $L_W$ less the total, per band, in decibels (at most 0).

PartialPlantContributions.plot(
    ax: Axes | None = None,
    *,
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Plot each part’s $L_W$ and their total, band by band.

Parameters

Returns: The axes. Requires matplotlib (pip install phonometry[plot]).

property

$L_W$ of the parts together, per band, in dB re 1 pW.

Constant (mapping).

PLANT_AIR_ABSORPTION_DB_PER_M = {31.5: 0.0, 63.0: 0.0, 125.0: 0.0, 250.0: 0.001, 500.0: 0.002, 1000.0: 0.005, 2000.0: 0.01, 4000.0: 0.026, 8000.0: 0.046}

plant_air_absorption_db_per_m(
    frequencies_hz: ArrayLike,
    *,
    temperature_c: float | None = None,
    relative_humidity_percent: float | None = None,
) -> NDArray[np.float64]

The attenuation coefficient of the air $\alpha$ of 10.7, in dB/m.

With no weather, Table 3 as printed, valid at 15 °C and 70 %. With the temperature and relative humidity at the time of the measurement, which Table 3 asks for when they “differ markedly” from those, the coefficient of ISO 3891:1978 Annex A (SAE ARP 866A) that Table 3 was taken from, evaluated at the one-third-octave band centred on each octave by phonometry.aircraft.atmospheric_absorption.arp866a_attenuation (the parabolic reading of its Table 1 that reproduces ISO 3891 Table 10) and turned from dB/100 m into dB/m. ISO 3891 gives no evaluation frequency below 50 Hz, so the 31,5 Hz band keeps the 0 of Table 3.

The two do not meet at 15 °C and 70 %: the formula gives 0,000 59 dB/m at 125 Hz, 0,025 05 dB/m at 4 kHz and 0,061 dB/m at 8 kHz where Table 3 prints 0, 0,026 and 0,046, and ISO 3891 Table 9 itself prints 0,1, 2,5 and 6,1 dB/100 m there. The other rows agree to the printed digit. In the sound power the 8 kHz row is a step of $0,5\times 0,0148\sqrt{S_{\mathrm{m}}}\approx 0,0074\sqrt{S_{\mathrm{m}}}$ dB between omitting the weather and passing 15 °C and 70 %, 1,4 dB over 36 800 m². Pass the weather only when it differs markedly from 15 °C and 70 %, as Table 3 asks; the standard sets no number for “markedly”.

Parameters

Returns: $\alpha$ per band, in dB/m.

Raises

Constant (mapping).

PLANT_BACKGROUND_CORRECTION_DB = {6: 1.0, 7: 1.0, 8: 1.0, 9: 0.5, 10: 0.5}

plant_background_correction_db(
    level_difference_db: ArrayLike,
) -> float | NDArray[np.float64]

The background correction of Table 2, to subtract from the level measured.

The table is printed in whole decibels: 1 dB for a difference of 6, 7 or 8 dB, 0,5 dB for 9 or 10 dB, 0 above 10 dB, and “Measurement invalid” below 6 dB. A difference between two rows is rounded to the nearest whole decibel, a half going up; the two ends are compared as printed, so 5,9 dB is invalid and 10,2 dB takes no correction. The difference is first settled to nine decimals, so 20,4 - 14,4 dB, 5,999 999 999 999 998 in binary, is the 6 dB it is, and 64,1 - 55,6 dB the 8,5 dB that rounds up.

Parameters

Returns: The correction, in decibels, a float for one difference and an array of the same shape otherwise.

Raises

plant_characteristic_height_m(
    source_heights_m: ArrayLike,
    *,
    low_source_count: int = 0,
) -> float

The characteristic height of the plant $H$, 9.2 c) and NOTE 7.

The mean height of the midpoints of the noise sources, derived from the equipment lists and the elevation drawings, $H=\frac{1}{n}{\sum }_{k=1}^n{h}_k$. NOTE 7 lets a plant with ten or more sources lower than 2 m count them approximately (to ±10 %) and take each at 1 m: pass those sources as low_source_count and leave them out of source_heights_m.

Parameters

Returns: $H$, in metres.

Raises

plant_mean_distance_limits_m(plant_area_m2: float) -> tuple[float, float]

The window of 9.1.1 a) for the average measurement distance $\bar{d}$.

$\bar{d}$ shall exceed $0,05\sqrt{S_{\mathrm{p}}}$ or 5 m, whichever is the greater, and shall not exceed $0,5\sqrt{S_{\mathrm{p}}}$ or 35 m, whichever is the lesser. The lower bound is strict, so the window is empty at or below $S_{\mathrm{p}}=100$ m² and at or above $490000$ m², where no contour meets the clause.

Parameters

Returns: (lower, upper) in metres: $\bar{d}$ must be above the first and at most the second.

Raises

plant_measurement_contour(
    plant_outline_m: ArrayLike,
    contour_m: ArrayLike,
    *,
    characteristic_height_m: float,
    position_count: int | None = None,
    omitted_positions: Sequence[int] = (),
) -> PlantMeasurementContour

Lay the measurement positions on a contour round the plant area, 9.1.

The positions are spaced equally along the contour from its first vertex. With no position_count, the layout is the smallest that meets 9.1.1 c), $D_{\mathrm{m}}=l/N\le 2\bar{d}$, with $\bar{d}$ taken over that same layout, from three positions up. A layout of your own is given as position_count, and the positions that could not be measured, a river or a building in the way (9.1.2.4), as omitted_positions.

The contour is not required to meet 9.1.1 here: a first contour drawn on the plan and found wanting is how the procedure starts (9.1.2.3, NOTE 6). check_plant_measurement says whether it does.

Parameters

Returns: A PlantMeasurementContour.

Raises

Constant (mapping).

PLANT_METHOD_UNCERTAINTY_DB = {0.05: (-3.5, 3.0), 0.1: (-2.5, 2.5), 0.2: (-2.5, 2.0), 0.5: (-2.0, 1.5)}

plant_method_uncertainty_db(distance_ratio: float) -> tuple[float, float]

The uncertainty inherent in the method, Table 1: a 95 % confidence interval for one determination, as (lower, upper) in decibels.

Table 1 prints four rows of $\bar{d}/\sqrt{S_{\mathrm{p}}}$ and says nothing of the ratios between them. The interval narrows as the ratio grows, so a ratio between two rows takes the row at or below it, the wider of the two; nothing narrower than a printed row is claimed. The range of the table, 0,05 to 0,5, is the range 9.1.1 a) allows.

NOTE 1 adds that where the background corrections of 9.5.4 cannot be applied, the uncertainty may be greater than the table’s.

Parameters

Returns: (lower, upper), for example (-3.5, 3.0) at 0,05.

Raises

plant_microphone_height_m(
    characteristic_height_m: float,
    measurement_area_m2: float,
) -> float

The microphone height of 9.3: $h=H+0,025\sqrt{S_{\mathrm{m}}}$ or 5 m, whichever is the greater.

Where this height cannot be reached for practical reasons, 9.3 asks for the microphone as high as possible above 5 m and for the fact to be reported; check_plant_measurement reports it.

Parameters

Returns: $h$, in metres.

Raises

plant_sound_power(
    levels_db: ArrayLike,
    frequencies_hz: ArrayLike,
    *,
    measurement_area_m2: float,
    contour_length_m: float,
    microphone_height_m: float,
    mean_distance_m: float,
    plant_area_m2: float,
    background_levels_db: ArrayLike | None = None,
    directional_microphone_angle_deg: float | ArrayLike | None = None,
    temperature_c: float | None = None,
    relative_humidity_percent: float | None = None,
) -> PlantSoundPowerResult

The octave-band and A-weighted sound power level of a plant, clause 10.

Steps 1 to 9 of clause 10 on the levels read round the contour. With a background given, every level is first corrected by Table 2 (9.5.4). The levels are energy-averaged per band (step 1); where one exceeds the average by more than 5 dB, 10.2 asks for a contour further from the plant, and where that is not practicable replaces each such level by the average plus 5 dB and averages again (steps 2 and 3), which is done here with a SoundPowerWarning, the result recording which levels were replaced. Steps 4 to 7 add the area, proximity, microphone and air absorption terms, step 8 sums them into $L_W$ and step 9 into $L_{W\mathrm{A}}$; the module docstring writes them out.

The geometry is the one 9.2 measures on the plot plan, to within ±5 %; PlantMeasurementContour.sound_power supplies it from polygons.

Parameters

Returns: A PlantSoundPowerResult.

Raises

plant_steady_reading_db(maximum_db: float, minimum_db: float) -> float

The level read on a sound level meter from a steady noise, 9.5.2.

With time weighting S, a needle that swings over less than 5 dB marks the noise as steady for the standard, and the level is the arithmetic mean of the maximum and the minimum over the observation. A wider swing makes the noise non-steady, and 9.5.2 then asks for an integrating instrument instead (9.5.3), whose steady $L_{\mathrm{eq},T}$ is the level used; leq_range_db of check_plant_measurement judges that one.

Parameters

Returns: The level, in decibels.

Raises

PlantMeasurementCheck(requirements: tuple[PlantRequirement, ...])

The arrangement and the readings of an ISO 8297 measurement against the requirements of the standard.

Attributes

property

The advisory requirements that do not hold, which the report states.

property

The requirements that are not advisory and do not hold.

property

Whether every requirement that is not advisory holds.

True says the contour, the positions, the microphones and the readings meet what ISO 8297 requires of them; the advisory rows that do not hold (deviations) still go in the report.

PlantMeasurementCheck.plot(
    ax: Axes | None = None,
    *,
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Plot how far each requirement is inside or outside its limit.

Parameters

Returns: The axes. Requires matplotlib (pip install phonometry[plot]).

PlantMeasurementCheck.requirement(key: str) -> PlantRequirement

The requirement with this key.

Parameters

Returns: The requirement.

Raises

PlantMeasurementContour(
    plant_outline_m: NDArray[np.float64],
    contour_m: NDArray[np.float64],
    characteristic_height_m: float,
    position_count: int,
    omitted_positions: tuple[int, ...] = (),
)

A measurement contour round a plant area on the plot plan, clauses 9.1 to 9.4.

The plant area and the contour are polygons in metres, in any consistent plane coordinates; the contour encloses the plant and does not touch it. The layout is position_count positions spaced equally along the contour from its first vertex (9.1.2.4, $D_{\mathrm{m}}=l/N$), of which those listed in omitted_positions could not be measured; every quantity below is taken over the positions that were.

Attributes

property

$l$, the length of the contour, in metres (9.2 a).

property

$\bar{d}/\sqrt{S_{\mathrm{p}}}$, the argument of Table 1.

property

The largest horizontal dimension of the plant area, in metres (1.2).

property

Every position of the equidistant layout, omitted ones included, (position_count, 2), in metres.

property

The window of 9.1.1 a) for this plant area, in metres.

property

$\bar{d}$, the average measurement distance, in metres (9.1.2.2).

property

$S_{\mathrm{m}}$, the total area the contour encloses, plant included, in square metres (3.4).

property

The distance from the plant centre beyond which 0.2 a) lets the result stand for a point source: 1,5 times the largest dimension, in metres.

property

The point of the plant perimeter nearest each measured position, (N, 2), in metres: the other end of each $d_i$.

property

The share of the layout left out, in percent (9.1.2.4).

property

$S_{\mathrm{p}}$, the plant area, in square metres (3.3).

property

The geometrical centre of the plant area, where 0.2 a) places the point source that stands for the plant, in metres.

PlantMeasurementContour.plot(
    ax: Axes | None = None,
    *,
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Draw the plan: plant area, contour, positions and their microphone directions, in the manner of Figure 1.

Parameters

Returns: The axes. Requires matplotlib (pip install phonometry[plot]).

property

$D_{\mathrm{m}}$, the distance between adjacent positions of the layout along the contour, in metres (3.6).

property

$h$ of 9.3 for this contour and plant, in metres.

PlantMeasurementContour.sound_power(
    levels_db: ArrayLike,
    frequencies_hz: ArrayLike,
    *,
    microphone_height_m: float | None = None,
    background_levels_db: ArrayLike | None = None,
    directional_microphone_angle_deg: float | ArrayLike | None = None,
    temperature_c: float | None = None,
    relative_humidity_percent: float | None = None,
) -> PlantSoundPowerResult

Run clause 10 on the levels read at the measured positions of this contour.

plant_sound_power with the geometry of the contour; see there.

Parameters

Returns: A PlantSoundPowerResult.

Raises

PlantRequirement(
    key: str,
    clause: str,
    description: str,
    value: float,
    comparison: str,
    limit: float,
    unit: str,
    holds: bool,
    advisory: bool = False,
    tolerance: float = 0.0,
)

One requirement of ISO 8297 held against the measurement.

Attributes

property

How far the value is inside the limit, as a fraction of the limit: positive where it holds by the comparison, negative where it does not. For "=" it is the room left inside the tolerance.

PlantSoundPowerResult(
    frequencies_hz: NDArray[np.float64],
    measured_levels_db: NDArray[np.float64],
    background_levels_db: NDArray[np.float64] | None,
    measurement_area_m2: float,
    contour_length_m: float,
    microphone_height_m: float,
    mean_distance_m: float,
    plant_area_m2: float,
    *,
    directional_microphone_angle_deg: NDArray[np.float64] | None = None,
    temperature_c: float | None = None,
    relative_humidity_percent: float | None = None,
)

The sound power level of a plant for the evaluation of levels in the environment, clause 10 of ISO 8297.

The fields are the readings and the geometry the calculation was made from; every step of clause 10 is derived from them on request, so a result cannot carry a level that disagrees with its own inputs.

Attributes

property

The bands summed into $L_{W\mathrm{A}}$: those the octave table of ISO 3744:2010 Annex E weights, 63 Hz to 8 kHz. A 31,5 Hz band, which NOTE 8 makes optional, is left out.

property

$L_{W\mathrm{A}}=10\lg {\sum }_{j}10^{0,1(L_{Wj}+C_j)}$, in dB re 1 pW (10.9).

property

$\alpha$ per band, in dB/m (10.7, Table 3).

property

$\Delta L_{\alpha }=0,5\alpha \sqrt{S_{\mathrm{m}}}$ per band, in decibels (10.7).

property

$\Delta L_{\mathrm{S}}=10\lg [(2S_{\mathrm{m}}+hl)/S_0]$, in decibels (10.4).

property

The Table 2 correction subtracted at each position and band, in decibels; None with no background.

property

The level with the plant operating less the background, per position and band, in decibels; None with no background.

property

Per position and band, whether $L_{pi}$ exceeds $\overline{L_p}$ by more than 5 dB and was replaced (10.2).

The excess is settled to nine decimals first: a level 5 dB above the energy mean comes out of the arithmetic a unit or two of the last place of the levels either side of 5, which side depending on the machine, and is not replaced.

property

$\overline{L_p^{\ast }}$ of 10.3, the average after replacing each capped level by $\overline{L_p}+5$ dB; equal to $\overline{L_p}$ in a band with nothing capped.

property

$\bar{d}/\sqrt{S_{\mathrm{p}}}$, the argument of Table 1.

property

$L_{pi}$, the levels corrected for the background (9.5.4), (N, bands), in decibels.

property

$\overline{L_p}$, the energy average round the contour, per band (10.1), in decibels.

property

$\Delta L_{\mathrm{M}}=3(1-\theta /90)$ per band, 0 for an omnidirectional microphone, in decibels (10.6).

property

$\Delta L_{\mathrm{F}}=\lg [\bar{d}/(4\sqrt{S_{\mathrm{p}}})]$, in decibels (10.5).

PlantSoundPowerResult.plot(
    ax: Axes | None = None,
    *,
    language: str = 'en',
    **kwargs: Any,
) -> Axes

Plot the octave-band $L_W$ beside the contour average it was built from, with $L_{W\mathrm{A}}$ in the title.

Parameters

Returns: The axes. Requires matplotlib (pip install phonometry[plot]).

property

$L_W$ per octave band, in dB re 1 pW (10.8).

property

Whether 10.2 and 10.3 changed anything: then $\overline{L_p^{\ast }}$ replaces $\overline{L_p}$ in 10.8.

property

The 95 % interval of Table 1 as (lower, upper) in decibels, or None where the distance ratio is outside the table (and outside 9.1.1 a).