Time Selective Measurements with a Logarithmically Swept Sine
Author: Martin Rung
A time selective measurement of a frequency response is (directly or indirectly) based on a measurement of the impulse response, where a well-defined time window is applied to the impulse response. The frequency response is simply the Fourier transform of the impulse response. Time selective measurements are often used in electroacoustics to make simulated free-field measurements of transducers. This is to isolate the directly transmitted, “freefield” sound from reflections due to the surroundings. By using a time window applied to the impulse response, it is
possible to obtain results similar to those obtained in a non-echoic environment.