Binaural intelligibility prediction based on the speech transmission index

Although the speech transmission index STI is a well-accepted and standardized method for objective prediction of speech intelligibility in a wide range of environments and applications, it is essentially a monaural model. Advantages of binaural hearing in speech intelligibility are disregarded. In specific conditions, this leads to considerable...

Study of an automated procedure for a Dutch sentence test for the measurement of the speech reception threshold in noise

A procedure was developed for the automated measurement of the speech reception threshold in stationary noise (SRTn), which can be administered by the subjects themselves using a computer. The procedure was based on the SRTn test for Dutch developed by Plomp and Mimpen [(1979). “Improving the reliability of testing the speech reception threshold...

Prediction of speech intelligibility for public address systems in traffic tunnels

Traffic tunnels are generally hostile acoustic environments, both in terms of reverberation and ambient noise levels. Public address (PA) systems used to convey spoken warnings must meet stringent design requirements in order to produce sufficiently intelligible speech. To be able to predict PA system performance at tunnel design time, two di...

Objective measurement of the speech transmission quality of vocoders by means of the Speech Transmission Index

Nearly all types of military speech communication involve the use of so-called (narrow band) voice coders or vocoders. Usually the Speech Transmission Index (STI) uses artificial test signals, which can not be reproduced by vocoders with the usual fidelity. Therefore the STI is not able to evaluate vocoders at this time. Although it is...

Using the Speech Transmission Index for predicting non-native speech intelligibility

While the Speech Transmission Index ~STI! is widely applied for prediction of speech intelligibility in room acoustics and telecommunication engineering, it is unclear how to interpret STI values when non-native talkers or listeners are involved. Based on subjectively measured psychometric functions for sentence intelligibility in noise, for...

Effect of talker and speaking style on the Speech Transmission Index (L)

The Speech Transmission Index (STI) is routinely applied for predicting the intelligibility of messages (sentences) in noise and reverberation. Despite clear evidence that the STI is capable of doing so accurately, recent results indicate that the STI sometimes underestimates the effect of reverberation on sentence intelligibility. To...

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...

Validation of the revised STI-r method

The revised model for the speech transmission index (STIr, Speech Communication 28 (1999) 109), was validated with an independent set of 68 test conditions. For a subset of 18 conditions, including only additive noise and band-pass limiting, it was veri.ed that the STIr provides a good prediction of the CVC-word score. The additional...

Past, present and future of the speech transmission index

Table of contents Tammo's and Herman's Index. An introduction by Manfred R. Schroeder Chapter 1. The roots of the STI approach. Tammo Houtgast and Herman J.M. Steeneken: Introduction - Our first effort - Introduction of STI - Speech envelope spectrum and MTF - Further developments - Envelope modulation and the ear Chapter 2. Basics of the STI...

Balancing speech intelligibility versus sound exposure in selection of personal hearing protection equipment for Chinook aircrews

Background: Aircrews are often exposed to high ambient sound levels, especially in military aviation. Since long-term exposure to such noise may cause hearing damage, selection of adequate hearing protective devices is crucial. Such devices also affect speech intelligibility. When speech intelligibility and hearing protection lead to conflicting...

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...