Snapshot Archive

Intelligibility Evaluation of Speech Coding Standards

snapshot_evs Speech intelligibility is an important aspect of speech transmission but often when speech coding standards are compared only the quality is evaluated using perceptual tests. In this study, the performance of three wideband speech coding standards, adaptive multi-rate wideband (AMR-WB), G.718, and enhanced voice services (EVS), is evaluated in a subjective intelligibility test. The test covers different packet loss conditions as well as a near-end background noise condition. Additionally, an objective quality evaluation in different packet loss conditions is conducted. All of the test conditions extend beyond the specification range to evaluate the attainable performance of the codecs in extreme conditions. The results of the subjective tests show that both EVS and G.718 are better in terms of intelligibility than AMR-WB. EVS attains the same performance as G.718 with lower algorithmic delay. Get the paper here.

Read more on EVS research at the AudioLabs.

Score-Informed Source Separation

snapshot_sis One central problem in music signal processing is the decomposition of a given audio recording of polyphonic music into sound components that correspond to musical voices, instrument tracks, or individual note events. One main challenge arises from the fact that musical sources are highly correlated, share the same harmonies and follow the same rhythmic patterns. In current research, we use additional cues such as the musical score to support the separation process. The score also provides a natural way for a user to interact with the separated sound events. Read more