Conference Paper
Evaluation of a Speech-Based and Binaural Speech Transmission Index
AES Conference: 40th International Conference: Spatial Audio: Sense the Sound of Space · Paper 4-6 · October 2010
Abstract
A speech-based and binaural Speech Transmission Index is presented and evaluated in a variety of acoustical
degradations and spatial conditions. The proposed method facilitates the assessment of speech intelligibility
in classical room acoustics and electroacoustics by simply comparing a binaural speech recording in adverse
conditions with its clean original. Both the binaural processing stage and the speech-based Speech Trans-
mission Index method are e ective and computationally fast realizations. The central part of the binaural
processor forms a cross-correlation stage that is designed to replicate psychoacoustic data of binaural in-
teraction. Supplemented with the head shadow e ect, which is generated in a `better-ear' fashion, a fair
amount of the binaural advantage in speech intelligibility is modeled.
An evaluation of the method was performed in a battery of listening tests. These tests incorporated di erent
degradations, as e.g., stationary noise and
uctuation noise, a set of nonlinear signal alterations, including a
speech enhancement processor, and a multitude of spatial con gurations with di erent room acoustics and
with up to four interferers. As a result, the objective method o ers a stable prediction of the subjective
results in binaural speech intelligibility throughout most of the linear degradations. In spite of that, the
full account of the binaural advantage is not achieved by the current implementation of the method, which
suggests further research.
