< Prev		CONTENTS		Source		Next >

Impulse Response

In simple nonmathematical terms, the impulse response is the sound level versus time curve when the room has been excited by an impulse sound (e.g., a clap). Nowadays, it can be processed from measurements and computer simulations using dedicated software.

The impulse response can bring useful indications regarding the behavior of a room that goes far beyond the mere reverberation time value. It will indicate the various contributions from reflections, and using the time interval between initial signal emission and reflection arrival, it will then be possible to determine the path followed by that particular contribution. While the impulse response as a measurement result will sometimes need some head scratching to find out which path has been followed, as a computer simulation result it usually is possible to follow precisely such a path and take appropriate measures if need be.

Figure 6.1 shows an example from a badly treated Italian-style opera hall. Looking at the stylized impulse response, it can be seen that after the direct sound has reached the measurement point, there are a few reflections, and then there is a massive arrival of reflected sound; this comes from the fact that such a facility features a curved cupola, curved balconies, and

Example of stylized impulse response curve

Figure 6.1 Example of stylized impulse response curve.

a curved proscenium, whose reflections arrive near simultaneously more than 40 ms after the direct sound.

Source

< Prev		CONTENTS		Source		Next >

Impulse Response and Variance Decompositions
As in the univariate case, a VAR(p) process can be represented in the form of a vector moving average (VMA) process. where the k x k moving average matrices tys are determined recursively using (6.1.3). The elements of coefficient matrices tys mean effects of ut_s shocks on...
(Financial Econometrics)
Impulse Response Analysis
The impulse response function traces the effect of a one standard deviation shock to one of the variables on current and future values of all the endogenous variables. A shock to any variable in the system does not only affect that variable directly but is also transmitted to all of the endogenous variables...
(Perspectives on Economic Development and Policy in India: In Honour of Suresh D. Tendulkar)
Impulse response functions
The dynamic analysis was performed with impulse response functions. The short- run restrictions were imposed on reduced-form error terms ut in (13.1) and (13.7). In case of non-linear TVAR model, the analysis is simplified in that the impulse responses are linear regime-dependent under...
(Competitiveness and Economic Development in Europe: Prospects and Challenges)
Critical earthquake response of an elastic–perfectly plastic SDOF model under double impulse as a representative of near-fault ground motions
Critical excitation problems were posed independently by Dr. Drenick and Dr. Shinozuka in 1970 (Drenick 1970, Shinozuka 1970) and acknowledged as one of the important fields in applied mechanics. More detailed description on the essential features of the critical excitation problems can be found...
(An Impulse and Earthquake Energy Balance Approach in Nonlinear Structural Dynamics)
Design of stiffness and strength for specified velocity and period of double impulse and specified response ductility
It may be useful to provide a procedure (or flowchart) for the design of stiffness and strength for the specified velocity and period of the near-fault ground motion input and response ductility. This design concept comes from the design philosophy that, if we focus on the worst case of resonance, the...
(An Impulse and Earthquake Energy Balance Approach in Nonlinear Structural Dynamics)
Critical earthquake response of an elastic–perfectly plastic SDOF model under triple impulse as a representative of near-fault ground motions
In Chapters 1 and 2, the double impulse was introduced as a good representative of near-fault ground motions. In this chapter, a triple impulse is introduced and used as another representative of near-fault ground motions (Kojima and Takewaki 2015b). Historically, since the science-oriented setting...
(An Impulse and Earthquake Energy Balance Approach in Nonlinear Structural Dynamics)
Design of stiffness and strength for specified velocity and period of triple impulse and specified response ductility
As in the case of the double impulse as a substitute for the near-fault fling- step input, it may be meaningful to present a procedure (flowchart) for the design of stiffness and strength for the specified velocity and period of the near-fault forward-directivity input and the response ductility. This...
(An Impulse and Earthquake Energy Balance Approach in Nonlinear Structural Dynamics)
Approximate prediction of response ductility for specified design of stiffness and strength and specified velocity and period of triple impulse
Until Section 3.5, only the critical set of velocity and period of near-fault ground motion input and the corresponding critical response have been treated for a specified design of stiffness and strength. On the other hand, in Figure 3.15 Schematic diagram of prediction method of response ductility...
(An Impulse and Earthquake Energy Balance Approach in Nonlinear Structural Dynamics)
Comparison between maximum response to double impulse and that to triple impulse
Since it may be meaningful to show the comparison between the maximum response to the double impulse explained in Chapter 2 and that to the triple impulse, it is presented in this section. Figure 3.16 Comparison between maximum response to double impulse and that to triple impulse (Kojima et al....
(An Impulse and Earthquake Energy Balance Approach in Nonlinear Structural Dynamics)