Download Finite Volume Perspectives on Finite Difference Schemes and Boundary Formulations for Wave Simulation
Time-domain finite difference (FD) and digital waveguide mesh (DWM) methods have seen extensive exploration as techniques for physical modelling sound synthesis and artificial reverberation. Various formulations of these methods have been unified under the FD framework, but many discrete boundary models important in room acoustics applications have not been. In this paper, the finite volume (FV) framework is used to unify various FD and DWM topologies, as well as associated boundary models. Additional geometric insights on existing stability conditions provide guidance into the FV meshing pre-processing step necessary for the acoustic modelling of irregular and realistic room geometries. DWM “1-D” boundary terminations are shown, through an equivalent FV formulation, to have a consistent multidimensional interpretation that is approximated to second-order accuracy, however the geometry and wall admittances being approximated may vary from what is desired. It is also shown that certain re-entrant corner configurations can lead to instabilities and an alternative stable update is provided for one problematic configuration.
Download A Cross-Adaptive Dynamic Spectral Panning Technique
This work presents an algorithm that is able to achieve novel spatialization effects on multitrack audio signals. It relies on a crossadaptive framework that dynamically maps the azimuth positions of each track’s time-frequency bins with the goal of reducing masking between source signals by dynamically separating them across space. The outputs of this system are compared to traditional panning strategies in subjective evaluation, and it is seen that scores indicate it performs well as a novel effect that can be used in live sound applications and creative sound design or mixing.
Download Low-Delay Error Concealment with Low Computational Overhead for Audio over IP Applications
A major problem in low-latency Audio over IP transmission is the unpredictable impact of the underlying network, leading to jitter and packet loss. Typically, error concealment strategies are employed at the receiver to counteract audible artifacts produced by missing audio data resulting from the mentioned network characteristics. Known concealment methods tend to achieve only unsatisfactory audio quality or cause high computational costs. Hence, this study aims at finding a new low-cost concealment strategy using simplest algorithms. The proposed system basically consists of an period extraction and alignment module to synthesize concealment signals from previous data. The audio quality is evaluated in form of automated measurements using PEAQ. Furthermore, the system’s complexity is analyzed by drawing the computational costs of all required modules in all operating modes and comparing its computational load versus another concealment method based on auto-regressive modeling.
Download Categorisation of Distortion Profiles in Relation to Audio Quality
Since digital audio is encoded as discrete samples of the audio waveform, much can be said about a recording by the statistical properties of these samples. In this paper, a dataset of CD audio samples is analysed; the probability mass function of each audio clip informs a feature set which describes attributes of the musical recording related to loudness, dynamics and distortion. This allows musical recordings to be classified according to their “distortion character”, a concept which describes the nature of amplitude distortion in mastered audio. A subjective test was designed in which such recordings were rated according to the perception of their audio quality. It is shown that participants can discern between three different distortion characters; ratings of audio quality were significantly different (F (1, 2) = 5.72, p < 0.001, η 2 = 0.008) as were the words used to describe the attributes on which quality was assessed (χ2 (8, N = 547) = 33.28, p < 0.001). This expands upon previous work showing links between the effects of dynamic range compression and audio quality in musical recordings, by highlighting perceptual differences.