Calculating traffic noise reduction at long distance using diffracting elements

A series of resonators alongside a road or railway can be used to diffract noise upwards to create a zone of noise reduction behind the elements. The company 4Silence developed the so-called Whisstone, a concrete block with 18 resonators of different depths designed to operate in a broad frequency range. Several measurements at short distance,...

A barrier for low frequency noise from starting aircraft: Comparison between numerical and scale model results

Amsterdam Airport Schiphol has organized a competition to design a noise mitigating measure along the 'Polderbaan' runway. Its main goal is to reduce the low frequency (LF) ground noise from starting aircraft. The winning concept is a flexible parabolic shaped noise barrier positioned relatively close to the runway. There is a large distance...

An acoustical model based monitoring network

In this paper the approach for an acoustical model based monitoring network is demonstrated. This network is capable of reconstructing a noise map, based on the combination of measured sound levels and an acoustic model of the area. By pre-calculating the sound attenuation within the network the noise map can be shown in real-time. The...

Mitigation of low-frequency groundnoise from runways

With the extra runway at Amsterdam Schiphol Airport, introduced in 2003, the noise nuisance for local residents increased due to increased groundnoise. In a case study the effect of enhanced ground absorption on the propagation of low-frequency noise from aircraft ground operations, e.g. departing aircraft, has been investigated. The study was...

Phoneme-group specific octave-band weights in predicting speech intelligibility

In an earlier study we derived robust frequency-weighting functions for prediction of the intelligibility of short nonsense words.These frequency-weighting functions are applied for prediction of intelligibility such as with the speech transmission index (STI).Six independent experiments revealed essentially similar frequency-weighting functions...

Mutual dependence of the octave-band weights in predicting speech intelligibility

Current objective measures for predicting the intelligibility of speech by an index assume that this can be obtained by simple addition of the contributions of individual frequency bands. The Articulation Index (AI, and the related Speech Intelligibility Index), and the Speech Transmission Index (STI) are based on this assumption. There is...