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phonometry

Rooms and buildings

This section covers sound in the built environment, and it splits along a natural line: what happens inside one room, and what passes between rooms. Inside a room, the governing quantity is absorption: it sets the reverberation time and the clarity that room acoustics measures (ISO 3382) and predicts (Sabine and its refinements, EN 12354-6), while the background noise the room settles into is rated against criterion curves (ANSI/ASA S12.2). Between rooms, the governing quantity is insulation: how much airborne and impact sound a partition and its flanking paths transmit, measured in the field (ISO 16283) or the laboratory (ISO 10140) and predicted from element data (EN 12354).

Both halves consume coefficients measured elsewhere: the Materials and surfaces section characterises the absorption, impedance and scattering data that the room and insulation predictions here rely on.

Start with Measuring the Room Impulse Response and Room Acoustics: the impulse response the first acquires and the parameters the second derives are the vocabulary the rest of the section speaks. If your interest is insulation, read Field Insulation Measurement (ISO 16283) next, and note that impact sources other than the tapping machine have their own page, since ISO 16283-2 is the clause a field engineer usually arrives with; if it is design-stage prediction, go to Reverberation-time prediction (Sabine, Eyring, Arau) and Predicting Sound Insulation (EN 12354).

Room acoustics

Section titled “Room acoustics”

The sound field inside a single room: measured from an impulse response, rated against criterion curves, and predicted from volume and absorption.

Sound insulation

Section titled “Sound insulation”

Airborne and impact insulation: measured in the building, characterised in the laboratory, and predicted from element data.

Insulation design

Section titled “Insulation design”

The same quantities before the building exists: predicted from element data, and from the physics of the element itself.

What this section does not cover

Section titled “What this section does not cover”

  • The library starts after the microphone and stops before the geometry. On the measurement side, position averaging happens once positions are supplied — the insulation functions energy-average per-position spectra for you — but nothing verifies how the measurement was made: the position counts and placements, the low-frequency procedures and the test-facility qualifications of ISO 16283, ISO 10140 and ISO 3382 are the operator’s job. So is measuring the background noise: only the ISO 10140-4 laboratory correction is implemented, warning when its 6 dB floor is broken, and field levels must arrive already corrected. On the prediction side, the element ratings, the junction indices and the covering improvements are inputs you supply from measurement or from a standard’s own annex; none is derived from a drawing.

  • Nothing here is a wave solver or a room model. There is no geometry importer, no material database, no ray tracer and no auralisation: the room pages take dimensions, absorption coefficients and impulse responses and give back parameters, and the image-source model is specular only. An actual low-frequency field in a real shape is wave simulation.

  • And a prediction is not a verdict. The single-number ratings and the national indices are computed here, but the limit values they are judged against are national — the Spanish code is implemented as a worked example of one such framework, not as the rule everywhere — and the requirement always comes from your regulation.

Before and after these pages

Section titled “Before and after these pages”

Every quantity on these pages starts from band levels or from a filtered impulse response, so the calibration, weighting and fractional-octave filtering behind them are in Signal analysis, and Build a sound level meter runs that chain end to end on one runnable page. The derivations sit in Rooms and buildings theory, from the Schroeder integration to the EN 12354 path sums.

If you arrived here from a search and want the shape of the whole library, What do you need to measure? indexes it by the job and All guides lists every page with a line on each.

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