WTIMIT: The TIMIT Speech Corpus Transmitted Over The 3G AMR Wideband Mobile Network
Patrick Bauer, David Scheler, Tim Fingscheidt · 2010
In anticipation of upcoming mobile telephony services with higher speech quality, a wideband (50 Hz to 7 kHz) mobile telephony derivative of TIMIT has been recorded called WTIMIT.It opens up various scientific investigations; e.g., on speech quality and intelligibility, as well as on wideband upgrades of network-side interactive voice response (IVR) systems with retrained or bandwidth-extended acoustic models for automatic speech recognition (ASR).Wideband telephony could enable network-side speech recognition applications such as remote dictation or spelling without the need of distributed speech recognition techniques.The WTIMIT corpus was transmitted via two prepared Nokia 6220 mobile phones over T-Mobile's 3G wideband mobile network in The Hague, The Netherlands, employing the Adaptive Multirate Wideband (AMR-WB) speech codec.The paper presents observations of transmission effects and phoneme recognition experiments.It turns out that in the case of wideband telephony, server-side ASR should not be carried out by simply decimating received signals to 8 kHz and applying existent narrowband acoustic models.Nor do we recommend just simulating the AMR-WB codec for training of wideband acoustic models.Instead, real-world wideband telephony channel data (such as WTIMIT) provides the best training material for wideband IVR systems.