Source: https://jmrplens.github.io/phonometry/buildings/insulation/insulation-field/ # Field Insulation Measurement (ISO 16283) This guide continues from the [Room Acoustics guide](https://jmrplens.github.io/phonometry/buildings/rooms/room-acoustics/): the same impulse response, measured either side of a partition, yields its sound insulation. This page covers the engineering-grade measurement of ISO 16283 in the finished building: the airborne level differences $D$, $D_\mathrm{nT}$ and $R'$, the impact levels $L'_\mathrm{nT}$ and $L'_\mathrm{n}$, the field test report, and the ISO 12999-1 uncertainty that qualifies every field value. Three close relatives have guides of their own: the reference-curve engine behind every single number in [Insulation Ratings (ISO 717)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-ratings/), the building envelope in [Façade Sound Insulation](https://jmrplens.github.io/phonometry/buildings/insulation/facade-insulation/), and the quick octave-band route in [Sound Insulation Survey Method (ISO 10052)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-survey/). The laboratory characterisation of an element lives in [Laboratory Insulation Measurement](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-lab/) and the prediction of in-situ performance in [Predicting Sound Insulation (EN 12354)](https://jmrplens.github.io/phonometry/buildings/design/insulation-prediction/). ## Field airborne insulation (ISO 16283-1) To rate a wall or floor, measure the energy-average level in the **source** room ($L_1$) and the **receiving** room ($L_2$) per one-third-octave band and form the level difference $D = L_1 - L_2$. Two normalisations make it comparable between rooms. The **standardized level difference** references the receiving-room reverberation time $T$ to $T_0 = 0.5$ s (so with $T = 0.5$ s, $D_\mathrm{nT} = D$ exactly), and the **apparent sound reduction index** normalises by the partition area $S$ and the Sabine absorption area $A$: $$ D_\mathrm{nT} = D + 10 \log_{10} \frac{T}{T_0}, \qquad R' = D + 10 \log_{10} \frac{S}{A}, \qquad A = \frac{0.16\ V}{T}. $$ Positions are energy-averaged with $L = 10 \log_{10}\left( \frac{1}{n} \sum_i 10^{L_i/10} \right)$. The prime on $R'$ is a convention, not decoration: primed quantities ($R'$, $L'_\mathrm{n}$, $L'_\mathrm{nT}$) are measured **in the building** and include every flanking path, while the unprimed $R$ and $L_\mathrm{n}$ are laboratory properties of the element alone, measured with flanking suppressed. The full lab-to-field map lives in [Laboratory Insulation Measurement](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-lab/); the prediction that bridges the two is [EN 12354](https://jmrplens.github.io/phonometry/buildings/design/insulation-prediction/). ```python import numpy as np from phonometry import building # Energy-average several microphone positions in one room (dB) print(round(float(building.energy_average_level([60.0, 66.0])), 1)) # 64.0 # Field insulation per band; area S and volume V add R' l1 = np.full(16, 80.0) # source-room levels l2 = np.full(16, 40.0) # receiving-room levels t2 = np.full(16, 0.5) # receiving-room T (s) ins = building.airborne_insulation(l1, l2, t2, area=10.0, volume=50.0) print(round(float(ins.dnt[0]), 1)) # 40.0 (= D since T = T0) print(round(float(ins.r_prime[0]), 1)) # 38.0 # The single number comes from the ISO 717-1 engine of the ratings guide print(building.weighted_rating(ins.dnt).rating) # 40 DnT,w print(building.weighted_rating(ins.r_prime).rating) # 38 R'w ``` Compute `l1`, `l2` and `t2` on the same 16 one-third-octave bands from 100 Hz to 3150 Hz (obtain `t2` from `room_parameters(ir, fs, limits=(100, 3150), fraction=3).t30`, for example) and pass them to `airborne_insulation`. Feed that function's `dnt` (or `r_prime`) spectrum to `weighted_rating`, so every band aligns index-by-index with the ISO 717-1 reference curve. ### `airborne_insulation()` parameters | Parameter | Type | Units | Range / default | Notes | | :--- | :--- | :--- | :--- | :--- | | `l1` | 1D or 2D array | dB | one/band, or `(positions, bands)` | Source-room levels (2D is energy-averaged) | | `l2` | 1D or 2D array | dB | same band count | Receiving-room levels | | `t2` | 1D array | s | > 0, one per band | Receiving-room reverberation time | | `area` | float, optional | m² | > 0, with `volume` | Partition area $S$ (enables $R'$) | | `volume` | float, optional | m³ | > 0, with `area` | Receiving-room volume $V$ | | `t0` | float | s | default `0.5` | Reference reverberation time $T_0$ | `airborne_insulation()` returns an `AirborneInsulationResult` (`d`, `dnt`, `r_prime` or `None`). The reference-curve engine that turns any of those spectra into $R_\mathrm{w}$, $R'_\mathrm{w}$ or $D_\mathrm{nT,w}$, its spectrum adaptation terms and its enlarged-range variants are in [Insulation Ratings (ISO 717)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-ratings/). ## Field impact insulation (ISO 16283-2) Footstep noise is rated the other way round. Instead of how much a floor *blocks*, impact insulation measures how much a standardized **tapping machine** on the floor above puts into the room below, so a *higher* number is *worse*. The energy-average impact sound pressure level $L_\mathrm{i}$ in the receiving room is normalised like the airborne case, but with a sign flip on the reverberation term: $$ L'_\mathrm{nT} = L_\mathrm{i} - 10 \log_{10} \frac{T}{T_0}, \qquad L'_\mathrm{n} = L_\mathrm{i} + 10 \log_{10} \frac{A}{A_0}, \quad A_0 = 10\ \text{m}^2,\ A = \frac{0.16\ V}{T}. $$ The **standardized** impact level $L'_\mathrm{nT}$ ($T_0 = 0.5$ s for dwellings) needs only the receiving-room $T$, so with $T = 0.5$ s it equals $L_\mathrm{i}$; the **normalized** level $L'_\mathrm{n}$ (referenced to a 10 m² absorption area) also needs the receiving-room volume. Note the **minus** sign: more reverberation *lowers* $L'_\mathrm{nT}$, opposite to the airborne $D_\mathrm{nT}$. ```python import numpy as np from phonometry import building # 16 one-third-octave impact levels Li (100 Hz - 3150 Hz), dB, from the # ISO 717-2 Annex C worked example, and the receiving-room T per band. li = np.array([62.1, 63.2, 63.5, 66.2, 68.5, 70.0, 71.7, 73.1, 73.8, 73.5, 73.8, 73.3, 73.1, 73.0, 72.4, 71.2]) t2 = np.full(16, 0.5) imp = building.impact_insulation(li, t2, volume=50.0) print(round(float(imp.l_n_t[0]), 1)) # 62.1 (= Li since T = T0) print(round(float(imp.l_n[0]), 1)) # 64.1 normalized to A0 = 10 m^2 # Weighted impact rating + spectrum adaptation term CI (ISO 717-2) res_imp = building.weighted_impact_rating(imp.l_n_t) print(res_imp.rating, res_imp.ci, res_imp.unfavourable_sum) # 79 -11 28.0 -> L'nT,w(CI)=79(-11) # Octave-band data carry the extra -5 dB reduction (Clause 4.3.2) octave = np.array([65.3, 64.5, 58.0, 55.8, 43.0]) print(building.weighted_impact_rating(octave).rating) # 54 ``` Feed `impact_insulation`'s `l_n_t` (or `l_n`) straight into `weighted_impact_rating`; the rating and $C_\mathrm{I}$ reproduce the ISO 717-2 Annex C values (thirds $L'_\mathrm{nT,w} = 79$, $C_\mathrm{I} = -11$; octave 54, $C_\mathrm{I} = 0$). ### `impact_insulation()` parameters | Parameter | Type | Units | Range / default | Notes | | :--- | :--- | :--- | :--- | :--- | | `li` | 1D or 2D array | dB | one/band, or `(positions, bands)` | Energy-average impact SPL (2D is averaged over positions) | | `t2` | 1D array | s | > 0, one per band | Receiving-room reverberation time | | `volume` | float, optional | m³ | > 0 | Receiving-room $V$ (enables $L'_\mathrm{n}$) | | `t0` | float | s | default `0.5` | Reference reverberation time $T_0$ | `impact_insulation()` returns an `ImpactInsulationResult` (`l_n_t`, `l_n` or `None`); the ISO 717-2 side of the chain is in [Insulation Ratings (ISO 717)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-ratings/). ## ISO 16283 field test report (`.report()`) The per-band field results write the test report of ISO 16283-1:2014 / ISO 16283-2:2020 Clause 14 directly, laid out like the recommended results forms (Annex B / Annex C) and the accredited field reports built on them. `AirborneInsulationResult.report()` renders the standardized level difference $D_\mathrm{nT}$ fiche (Figure B.1) or, with `quantity="r_prime"`, the apparent sound reduction index $R'$ fiche (Figure B.2); `ImpactInsulationResult.report()` renders the standardized $L'_\mathrm{nT}$ fiche (Figure C.1) or, with `quantity="l_n"`, the normalized $L'_\mathrm{n}$ fiche (Figure C.2). Each fiche names the field standard in its basis line, evaluates the ISO 717-1 / ISO 717-2 single-number rating over the 16 core one-third-octave bands (100-3150 Hz), states the quantity to one decimal place both in tabular form and as a curve against the shifted reference curve (Clause 12), boxes the field rating (`DnT,w (C; Ctr)`, `R'w (C; Ctr)`, `L'nT,w (CI)` or `L'n,w (CI)`) and prints the mandatory statement that the evaluation is based on field measurement results obtained by an engineering method. `verbose=True` swaps the two-column table for the per-band measurement chain (the energy-average $L_1$ and $L_2$, or $L_\mathrm{i}$, and the reverberation time $T$ beside the reported quantity), the content accredited field reports annex; it needs a result built by `airborne_insulation()` / `impact_insulation()`, which retain those inputs on the result (`l1`, `l2`/`li`, `t2`, `t0`). Metadata, the requirement verdict (airborne passes at or above it, impact at or below it), `language="es"` and the `phonometry[report]` extra behave exactly as in the ISO 717 fiche above. ```python import numpy as np from phonometry import building, ReportMetadata # Field airborne: source/receiving levels and T per one-third-octave band l1 = np.array([92.3, 93.1, 94.0, 94.4, 94.8, 95.0, 95.2, 95.4, 95.3, 95.1, 94.8, 94.4, 93.9, 93.3, 92.5, 91.6]) l2 = l1 - np.array([38.2, 40.1, 42.6, 45.2, 47.8, 50.1, 52.3, 54.0, 55.6, 57.1, 58.2, 59.0, 59.6, 60.1, 60.3, 59.8]) t2 = np.array([0.62, 0.58, 0.55, 0.53, 0.52, 0.50, 0.49, 0.48, 0.47, 0.46, 0.45, 0.45, 0.44, 0.43, 0.43, 0.42]) field = building.airborne_insulation(l1, l2, t2, area=12.5, volume=30.4) field.plot() # per-band DnT (and R') of the measured chain (needs matplotlib) metadata = ReportMetadata( specimen="Separating wall, 240 mm brick with independent lining", client="Example client", area=12.5, source_volume=32.1, receiving_volume=30.4, test_room="Dwelling A living room to dwelling B living room", test_date="2026-07-20", laboratory="Phonometry Reference Laboratory", report_id="PHN-2026-0143", requirement=50.0, # DnT,w >= 50 dB -> PASS/FAIL row ) field.report("DnTw_field.pdf", metadata=metadata) # DnT,w (C; Ctr) field.report("Rpw_field.pdf", quantity="r_prime", metadata=metadata) # R'w (C; Ctr) field.report("DnTw_chain.pdf", metadata=metadata, verbose=True) # f | L1 | L2 | T | DnT # Field impact: tapping-machine levels in the receiving room li = np.array([58.0, 60.5, 62.0, 63.5, 65.0, 66.0, 66.5, 66.0, 65.5, 65.0, 64.0, 62.0, 59.0, 56.0, 53.0, 50.0]) imp = building.impact_insulation(li, t2, volume=30.4) imp.report("LnTw_field.pdf", metadata=ReportMetadata(requirement=58.0)) # L'nT,w (CI) ``` *The receiving-room reverberation time turns the raw level difference $D$ into the standardized $D_\mathrm{nT}$ band by band; with $T$ above $T_0 = 0.5$ s across the range, the correction lifts the curve slightly. The rating box carries both single numbers of this measurement, $D_\mathrm{nT,w}$ and $R'_\mathrm{w}$.*

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```python import matplotlib.pyplot as plt import numpy as np from phonometry import building # Field airborne: source/receiving levels and T per one-third-octave band l1 = np.array([92.3, 93.1, 94.0, 94.4, 94.8, 95.0, 95.2, 95.4, 95.3, 95.1, 94.8, 94.4, 93.9, 93.3, 92.5, 91.6]) l2 = l1 - np.array([38.2, 40.1, 42.6, 45.2, 47.8, 50.1, 52.3, 54.0, 55.6, 57.1, 58.2, 59.0, 59.6, 60.1, 60.3, 59.8]) t2 = np.array([0.62, 0.58, 0.55, 0.53, 0.52, 0.50, 0.49, 0.48, 0.47, 0.46, 0.45, 0.45, 0.44, 0.43, 0.43, 0.42]) field = building.airborne_insulation(l1, l2, t2, area=12.5, volume=30.4) # One line — the per-band DnT (and R') of the measured chain: field.plot() plt.show() # By hand, from the result's fields: bands = [100, 125, 160, 200, 250, 315, 400, 500, 630, 800, 1000, 1250, 1600, 2000, 2500, 3150] x = np.arange(len(bands)) w = building.weighted_rating(field.dnt) fig, ax = plt.subplots() ax.fill_between(x, field.d, field.dnt, alpha=0.2, label="10 log10(T/T0)") ax.plot(x, field.d, "--o", label="D (level difference)") ax.plot(x, field.dnt, "-s", label="DnT (standardized)") ax.set_xticks(x, [str(b) for b in bands], rotation=45) ax.set(xlabel="Frequency [Hz]", ylabel="Level difference [dB]", title=f"DnT,w = {w.rating} dB (C={w.c:+d}; Ctr={w.ctr:+d})") ax.legend() plt.show() ```

Rendered examples of both field fiches, regenerated with `make reports`, are kept in the repository. Click either preview to open the PDF: [](https://raw.githubusercontent.com/jmrplens/phonometry/main/.github/reports/iso16283_airborne_example.pdf) *Field airborne fiche (`AirborneInsulationResult.report`), DnT,w (C; Ctr).* [](https://raw.githubusercontent.com/jmrplens/phonometry/main/.github/reports/iso16283_impact_example.pdf) *Field impact fiche (`ImpactInsulationResult.report`), L'nT,w (CI).* ## Measurement uncertainty (ISO 12999-1) A rating without an uncertainty is only half a result. ISO 12999-1 does not re-measure anything; it tabulates the **standard uncertainty** $u$ of every sound-insulation quantity, derived from inter-laboratory tests, and prescribes how to expand and combine it. Which standard deviation is $u$ depends on the **measurement situation** (Clause 5.2): | Situation | Meaning | Standard uncertainty $u$ | | :--- | :--- | :--- | | **A** | laboratory characterisation (ISO 10140) | reproducibility $\sigma_\mathrm{R}$ | | **B** | same location, different teams | in-situ $\sigma_\mathrm{situ}$ | | **C** | same location, same operator repeated | repeatability $\sigma_\mathrm{r}$ | The expanded uncertainty is $U = k\ u$ (Formula 2) with the coverage factor $k$ of Table 8. A two-sided interval $Y = y \pm U$ (Formula 3, $k = 1.96$ at 95 %) *reports* a value; the **one-sided** factor ($k = 1.65$ at 95 %) *declares conformity* with a requirement (Formulae 4/5). ```python from phonometry import building # Situation B (same building, different teams) -> the in-situ standard deviation. print(building.single_number_uncertainty("r_w", "B")) # 0.9 dB (Table 3) u = building.band_uncertainty("airborne", "B") # per-band u (Table 2) print(len(u.frequencies), u.uncertainties[10]) # 21 1.1 (the 500 Hz band) u.plot() # the per-band u(f) spectrum of Table 2 (needs matplotlib) # Report R'w = 52 dB with a two-sided 95 % interval (k = 1.96, Table 8): uv = building.uncertain_value(52.0, "rprime_w", "B") # aliases resolve to r_w print(uv.coverage_factor, round(uv.expanded_uncertainty, 1)) # 1.96 1.8 print(round(uv.lower, 1), round(uv.upper, 1)) # 50.2 53.8 -> 52 ± 1.8 dB # Declaring conformity uses the ONE-sided factor (k = 1.65): does R'w provably # clear a 50 dB requirement? uc = building.uncertain_value(52.0, "rprime_w", "B", one_sided=True) print(building.satisfies_lower_requirement(52.0, uc.expanded_uncertainty, 50.0)) # True ``` Impact quantities offer situations B/C only (Table 4, no 500 Hz band in the 2020 edition), and $\Delta L$ only situation A. Descriptors are case-insensitive with aliases (`rprime_w`/`dnt_w`→`r_w`, `lprime_n_w`→`ln_w`); combine independent components in quadrature with `combine_uncertainties`, and reduce by $m$ independent measurements with `reduce_by_independent_measurements` ($u/\sqrt{m}$).

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```python import matplotlib.pyplot as plt from phonometry import building # The same R'w = 52 dB reported in each situation with its two-sided 95 % U. situations = ["A", "B", "C"] vals = [building.uncertain_value(52.0, "r_w", s) for s in situations] fig, ax = plt.subplots(figsize=(7, 4)) ax.errorbar(situations, [v.value for v in vals], yerr=[v.expanded_uncertainty for v in vals], fmt="o", capsize=8, color="tab:blue") for s, v in zip(situations, vals): ax.annotate(f"±{v.expanded_uncertainty:.1f}", (s, v.upper), textcoords="offset points", xytext=(8, 4)) ax.set_ylabel("R'w [dB]"); ax.set_xlabel("Measurement situation") ax.set_title("R'w = 52 dB with 95 % expanded uncertainty (ISO 12999-1)") fig.tight_layout() plt.show() ```

### `band_uncertainty()` / `single_number_uncertainty()` / `uncertain_value()` parameters | Parameter | Type | Units | Range / default | Notes | | :--- | :--- | :--- | :--- | :--- | | `measurand` | str | — | `'airborne'` / `'impact'` / `'impact_reduction'` | Selects Table 2 / 4 / 6 | | `quantity` | str | — | `'r_w'`, `'ln_w'`, `'delta_lw'` (+ aliases, `+c`/`+ctr` variants) | Single-number descriptor | | `situation` | str | — | `'A'` / `'B'` / `'C'` | Measurement situation (Clause 5.2) | | `value` | float | dB | — | Best estimate $y$ to attach $U$ to | | `coverage` | float | — | default `0.95` | Confidence level (Table 8) | | `one_sided` | bool | — | default `False` | One-sided factor for conformity checks | | `upper_limit` | bool | — | default `False` | Select the $\sigma_\mathrm{R95}$ upper limit (airborne, situation A) | `band_uncertainty()` returns a `BandUncertainty` (`frequencies`, `uncertainties`, `.to_arrays()`); `single_number_uncertainty()` a float; `uncertain_value()` an `UncertainValue` (`value`, `standard_uncertainty`, `coverage_factor`, `expanded_uncertainty`, `.lower`, `.upper`). The read-only `COVERAGE_FACTORS` mapping exposes Table 8 keyed by `(confidence, one_sided)`. ## Beyond the two-room measurement Three measurements that used to share this page now have guides of their own, and a fourth sits alongside them. The building envelope, measured against the level 2 m in front of it and predicted from its elements, is [Façade Sound Insulation](https://jmrplens.github.io/phonometry/buildings/insulation/facade-insulation/). When a full engineering measurement is more than the question deserves, the octave-band control method is [Sound Insulation Survey Method (ISO 10052)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-survey/). Every single number quoted above comes from the reference curves of [Insulation Ratings (ISO 717)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-ratings/). And the sound-intensity route to the same quantities, which reads the transmitted power off the radiating face instead of the receiving-room level, is [Sound Insulation by Intensity (ISO 15186)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-intensity/). ## Quick answers ### What does DnT,w mean? $D_\mathrm{nT,w}$ is the weighted standardized level difference. Per one-third-octave band, $D_\mathrm{nT} = D + 10 \log_{10}(T/T_0)$ references the receiving-room reverberation time $T$ to $T_0 = 0.5$ s, with $D = L_1 - L_2$ the source-to-receiving level difference (ISO 16283-1). The ISO 717-1 reference-curve method then collapses the 16 bands from 100 Hz to 3150 Hz into the single number read at 500 Hz. ### What is the difference between R and R' in sound insulation? The prime marks where the measurement was made: primed quantities ($R'$, $L'_\mathrm{n}$, $L'_\mathrm{nT}$) are measured in the building and include every flanking path, while the unprimed $R$ and $L_\mathrm{n}$ are laboratory properties of the element alone, measured with flanking suppressed. In the field (ISO 16283-1), $R' = D + 10 \log_{10}(S/A)$ with partition area $S$ and Sabine absorption area $A = 0.16\ V/T$. ## References - Hopkins, C. (2007). *Sound insulation*. Butterworth-Heinemann. ISBN 978-0-7506-6526-1. [doi:10.4324/9780080550473](https://doi.org/10.4324/9780080550473). The comprehensive treatment of airborne and impact sound insulation: the measurement chains and the statistics of rooms behind the field quantities. - Vigran, T. E. (2008). *Building acoustics*. CRC Press. ISBN 978-0-415-42853-8. [doi:10.1201/9781482266016](https://doi.org/10.1201/9781482266016). A compact textbook companion for the sound-transmission physics behind these measurements. - International Organization for Standardization. (2014). *Acoustics — Field measurement of sound insulation in buildings and of building elements — Part 1: Airborne sound insulation* (ISO 16283-1:2014). [iso.org catalogue](https://www.iso.org/standard/55997.html). The field airborne method this page implements. - International Organization for Standardization. (2020). *Acoustics — Determination and application of measurement uncertainties in building acoustics — Part 1: Sound insulation* (ISO 12999-1:2020). [iso.org catalogue](https://www.iso.org/standard/73930.html). The standard uncertainties per measurement situation and the coverage factors that expand them. ## Standards ISO 16283-1:2014 and ISO 16283-2:2020, *Acoustics — Field measurement of sound insulation in buildings and of building elements*: the airborne and impact level differences, their normalisations and the Clause 14 test report; ISO 12999-1:2020, which tabulates the standard uncertainties per measurement situation and the coverage factors, and whose precision framework builds on ISO 5725 (context, not implemented directly). The single-number ratings quoted here are those of ISO 717-1 and ISO 717-2, and the façade part of the same ISO 16283 family (ISO 16283-3:2016) has its own page. **Not covered.** Every field function takes levels the caller has already corrected for background noise (ISO 16283-1 Clause 9.2). Measuring the background level — source off, same positions, same averaging — is the operator's job, and nothing here verifies that the 6 dB floor was met. (`background_correction` is the **ISO 10140-4** *laboratory* variant and does not match the field thresholds.) The position counts, distances and averaging of ISO 16283-1/-2, and the corner measurements of the low-frequency procedure, are documented above and checked nowhere: energy averaging happens once positions are supplied, but nothing verifies how many were taken, where, or that the 25 m³ trigger was even tested for. The Formula (12)/(13) combination of the low-frequency procedure is two lines of NumPy, not a library function. The other members of the family have their own pages: the façade part (ISO 16283-3), the survey method (ISO 10052), the rating engines (ISO 717-1/-2) and the sound-intensity route (**ISO 15186-1**/-2). ## See also - [Insulation Ratings (ISO 717)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-ratings/): the reference-curve engine behind every weighted single number on this page. - [Façade Sound Insulation](https://jmrplens.github.io/phonometry/buildings/insulation/facade-insulation/): the third part of ISO 16283, measured and predicted. - [Sound Insulation Survey Method (ISO 10052)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-survey/): the octave-band control method these engineering methods are the reference for. - [Laboratory Insulation Measurement](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-lab/): the ISO 10140 element characterisation these field quantities are compared against. - [Sound Insulation by Intensity (ISO 15186)](https://jmrplens.github.io/phonometry/buildings/insulation/insulation-intensity/): the direct-power route to the same field and laboratory indices. - [Predicting Sound Insulation (EN 12354)](https://jmrplens.github.io/phonometry/buildings/design/insulation-prediction/): the in-situ performance predicted from laboratory element data. - [Room Acoustics](https://jmrplens.github.io/phonometry/buildings/rooms/room-acoustics/): the room parameters and reverberation times this guide's insulation chain builds on. - [Levels](https://jmrplens.github.io/phonometry/signals/levels/levels/): energy averaging and the level metrics behind source/receiving-room levels. - [Filter Banks](https://jmrplens.github.io/phonometry/signals/filters/filter-banks/): the IEC 61260 fractional-octave filters used for the insulation spectra. - [Theory](https://jmrplens.github.io/phonometry/reference/theory/rooms-buildings/): the reference-curve derivation behind the weighted single-number ratings. - API reference: [`building.measurement.insulation`](https://jmrplens.github.io/phonometry/reference/api/building/insulation/) and [`building.measurement.uncertainty`](https://jmrplens.github.io/phonometry/reference/api/building/uncertainty/).