Revision, extension, and evaluation of a binaural speech intelligibility model

Abstract

This study presents revision, extension, and evaluation of a binaural speech intelligibility model (Beutelmann, R., and Brand, T. (2006). J. Acoust. Soc. Am. 120, 331-342) that yields accurate predictions of speech reception thresholds (SRTs) in the presence of a stationary noise source at arbitrary azimuths and in different rooms. The modified model is based on an analytical expression of binaural unmasking for arbitrary input signals and is computationally more efficient, while maintaining the prediction quality of the original model. An extension for nonstationary interferers was realized by applying the model to short time frames of the input signals and averaging over the predicted SRT results. Binaural SRTs from 8 normal-hearing and 12 hearing-impaired subjects, incorporating all combinations of four rooms, three source setups, and three noise types were measured and compared to the model's predictions. Depending on the noise type, the parametric correlation coefficients between observed and predicted SRTs were 0.80-0.93 for normal-hearing subjects and 0.59-0.80 for hearing-impaired subjects. The mean absolute prediction error was 3 dB for the mean normal-hearing data and 4 dB for the individual hearing-impaired data. 70% of the variance of the SRTs of hearing-impaired subjects could be explained by the model, which is based only on the audiogram.

Intelligibility for Binaural Speech with Discarded Low-SNR Speech Components

“…This would make previously undetectable speech elements audible and enable them to contribute to speech intelligibility. More recent models of speech intelligibility also make use of the concept of within-band improvement of SNR to model the spatial release from masking (e.g., Beutelmann et al 2010;Lavandier et al 2012;Wan et al 2014).…”

Binaural Glimpses at the Cocktail Party?

“…The further SI simulations (see below) were all based on the short-time BSIM by Beutelmann et al (2010). For a detailed description of the full model, the reader is referred to their publication.…”

“…described by the classic equalization-cancellation (EC) model (Durlach 1963). This model can account for binaural unmasking in psychoacoustics and was successfully combined with a speech intelligibility model (eSII; Rhebergen et al 2006) in the (short-time) binaural speech intelligibility model (BSIM; Beutelmann and Brand 2006;Beutelmann et al 2010). A conceptually similar approach was suggested by Lavandier and Culling (2010).…”

“…A conceptually similar approach was suggested by Lavandier and Culling (2010). The BSIM of Beutelmann et al (2010) can make use of short-time, per-channel ITDs and ILDs to gain a binaurally improved TMR at the output of the EC stage. Recently, Wan et al (2014) also suggested a short-time version of the EC model (STEC), additionally focusing on the advantages of binaural processing which adjusts to timevarying input waveforms.…”

“…These manipulations left long-term energetic masking effects unchanged but precluded the use of better-ear glimpses in the targeted frequency range. SI was compared to predictions of a state-ofthe-art binaural SI model (Beutelmann et al 2010) which allows for better-ear glimpses, and the contributions of individual model stages to overall SI were analysed.…”