Impact noise
In building acoustics noise generated by mechanical impact excitation like foot steps or hammer. According to ISO 140 impact noise transmitted in a building through the construction is measured using a standardized tapping machine. The measured sound pressure level Li in a room is called the impact

sound pressure level and expressed as normalized impact sound pressure level Ln=Li + 10 log(A/10 m2) (A is the equivalent absorption area of the room). See also structure borne noise.

Impact sound transmission
Sound transmission of impact noise through the building elements. Impact sound transmission happens if something is dropped on the floor or even just when someone is walking on the floor. Impact noise can be transmitted as vibrations in the building elements over a long distance and be radiated to rooms far away and not directly adjacent to the source room.

Impulse response
Measured or calculated sound pressure signal (versus time) in a receiving point, when an impulse is emitted in a source point. Knowing the impulse response, all acoustic local parameters can be calculated. (e.g. reverberation time, speech intelligibility,). The impulse response indicates all reflections between source point and receiving point.

Insertion loss
Sound attenuation of an element which is inserted in a construction. E.g. the attenuation of airborne duct sound inside a ventilation duct using a ducted silencer. The insertion loss is often measured as the difference of noise level in a receiving point with and without the considered element.

Intelligibility
See speech intelligibility

ISO 140

Acoustics -- Measurement of sound insulation in buildings

and of building elements
Part - 1 ... 18 - Definition of sound reduction index, impact noise and measurements (R, Dne, L)

Most relevant:
Part 3: Laboratory measurements of airborne sound insulation of building elements
Part 4: Field measurements of airborne sound insulation between room
Part 6: Laboratory measurements of impact sound insulation of floors
Part 7: Field measurements of impact sound insulation of floors

ISO 717

Acoustics -- Rating of sound insulation in buildings and

of building elements
Rw, (C, Ctr)
The Rw value (Weighted Sound Reduction Index) is calculated from 100 Hz to 3150 Hz based on results from e.g. ISO 140-3 measurements, different adaptation terms for extended frequency ranges and noise spectra available.
Ln,w
The Ln,w value (weighted normalized impact sound pressure level) is calculated from 100 Hz to 3150 Hz based on results from e.g. ISO 140-6 measurements

ISO 15186

Acoustics - Measurement of sound insulation in buildings and of building elements using sound intensity
ISO 15186-3:2002 specifies a sound intensity method to determine the sound reduction index and the element-normalized level difference of building elements at low frequencies. This method has significantly better reproducibility in a typical test facility than those of ISO 140-3, ISO 140-10 and ISO 15186-1. The results are more independent of the room dimensions of the laboratory and closer to values that would be measured between rooms of volume greater than 300 m3. ISO 15186-3 is applicable in the frequency range 50 Hz to 160 Hz but is mainly intended for the frequency range 50 Hz to 80 Hz.
The results found by the method of ISO 15186-3 can be combined with those of ISO 140-3 and ISO 15186-1 to produce data in the frequency range 50 Hz to 5 000 Hz.

ISO 10848

Acoustics - Laboratory measurement of the flanking transmission of airborne and impact sound between adjoining rooms

ISO 10848-2:2006 applies to light elements such as suspended ceilings, access floors, light uninterrupted facades or floating floors. The transmission from one room to another can be simultaneous through the test element and via the plenum, if any. With measurements according to ISO 10848-2:2006, the total sound transmission is measured, and it is not possible to separate the two kinds of transmission. ISO 10848-3:2006 applies to structurally connected light elements forming a T or X junction. The performance of the building components is expressed either as an overall quantity for the combination of elements and junction, or as the vibration reduction index of a junction.

ISO 354
Acoustics – Measurements of sound absorption in a reverberation room Measurement of sound bsorption coefficient in a diffuse field (room methode) 

ISO 11654
Acoustics – Sound absorbers for use in buildings – Rating of sound absorption. Calculation of ap (octave band values) and aw (weighted sound absorption) and definition of sound absorption classes A ... E.

ISO 10534

Acoustics - Determination of sound absorption coefficient and impedance in impedance tubes
Specifies a method for the determination of the sound absorption coefficient, reflection factor, surface impedance or admittance of materials and objects. The values are determined by evaluation of the standing wave pattern of a plane wave in a tube, which is generated by the superposition of an incident

sinusiodal plane wave with the plane wave reflected from the test object.

ISO 9052

Acoustics - Determination of dynamic stiffness
Relates to the unit area of resilient materials with smooth surfaces, including mineral wool. Does not apply to loadings lower than 0,4 kPa or greater than 4 kPa, that is not for materials in wall linings and not for machinery foundations. 

ISO 9053
Acoustics - Materials for acoustical applications -- Determination of airflow  resistance

ISO 3382
Acoustics – Measurement of room acoustic parameters
ISO_2923-1997 + ISO_2923_Cor Measurements of noise onboard vessels