Search results for "Reverberation"
showing 8 items of 18 documents
Nonnegative signal factorization with learnt instrument models for sound source separation in close-microphone recordings
2013
Close-microphone techniques are extensively employed in many live music recordings, allowing for interference rejection and reducing the amount of reverberation in the resulting instrument tracks. However, despite the use of directional microphones, the recorded tracks are not completely free from source interference, a problem which is commonly known as microphone leakage. While source separation methods are potentially a solution to this problem, few approaches take into account the huge amount of prior information available in this scenario. In fact, besides the special properties of close-microphone tracks, the knowledge on the number and type of instruments making up the mixture can al…
On the Robustness of Deep Features for Audio Event Classification in Adverse Environments
2018
Deep features, responses to complex input patterns learned within deep neural networks, have recently shown great performance in image recognition tasks, motivating their use for audio analysis tasks as well. These features provide multiple levels of abstraction which permit to select a sufficiently generalized layer to identify classes not seen during training. The generalization capability of such features is very useful due to the lack of complete labeled audio datasets. However, as opposed to classical hand-crafted features such as Mel-frequency cepstral coefficients (MFCCs), the performance impact of having an acoustically adverse environment has not been evaluated in detail. In this p…
Frequency-Sliding Generalized Cross-Correlation: A Sub-Band Time Delay Estimation Approach
2020
The generalized cross correlation (GCC) is regarded as the most popular approach for estimating the time difference of arrival (TDOA) between the signals received at two sensors. Time delay estimates are obtained by maximizing the GCC output, where the direct-path delay is usually observed as a prominent peak. Moreover, GCCs play also an important role in steered response power (SRP) localization algorithms, where the SRP functional can be written as an accumulation of the GCCs computed from multiple sensor pairs. Unfortunately, the accuracy of TDOA estimates is affected by multiple factors, including noise, reverberation and signal bandwidth. In this paper, a sub-band approach for time del…
Meticciamento regressivo: donne migranti e donne palermitane
2020
Lo studio proposto restringe in campo d’analisi a un quartiere dei più antichi e popolari di Palermo per descrivere e riflettere sull’interpretazione fornita dalle donne migranti provenienti dell’Africa alle discriminazioni di genere subite dai loro conterranei che ne orientano i codici comportamentali. Un aspetto inatteso che costituisce il cuore della ricerca è in ciò che è stato indicato come la fase aurorale di un meticciamento regressivo, e i cui effetti si sono caratterizzati con sfumature diverse proprio attraverso le riflessioni delle donne autoctone che valutavano positivamente i modelli comportamentali e l’agire quotidiano delle donne immigrate appartenenti alle loro cerchie di so…
On the performance of multi-GPU-based expert systems for acoustic localization involving massive microphone arrays
2015
Sound source localization is an important topic in expert systems involving microphone arrays, such as automatic camera steering systems, human-machine interaction, video gaming or audio surveillance. The Steered Response Power with Phase Transform (SRP-PHAT) algorithm is a well-known approach for sound source localization due to its robust performance in noisy and reverberant environments. This algorithm analyzes the sound power captured by an acoustic beamformer on a defined spatial grid, estimating the source location as the point that maximizes the output power. Since localization accuracy can be improved by using high-resolution spatial grids and a high number of microphones, accurate …
Perceived differences between natural and convolution reverberation types in 5.0 surround sound
2011
This Graduate Thesis investigates the perceived differences between natural and convolution reverberation in surround sound. Two spaces with distinct reverberation times were used for this study. Initially three musical excerpts from three instruments (Cello, Oboe, and Piano) were recorded in a dry studio environment. Then the Impulse Response (IR) of the spaces was captured using two methods: balloon burst and sine sweep. The dry excerpts were then recorded in the spaces to capture the natural reverberation pattern while the IRs were convolved with them to create the artificial reverberation excerpts. A listening test was then conducted using six perceptual scales to rate these 18 excerpts…
Experimental Characterization and Acoustic Correction of a Multipurpose Performance Hall: The Italian Theatre “Cavallino Bianco”
2022
This study presents the retrofit acoustic dq1esign of the Italian theatre “Cavallino Bianco”. In its historical configuration, the hall had a curved roof with a pressed-plant fiber ceiling, which was demolished and replaced with a wooden roof without a false ceiling, leading to an increase in volume and a worsening of the reverberation time. This study proposed the realization of a wave ceiling and the application of sound-absorbing and reflecting panels on the walls, which have already been implemented. These modifications have affected the acoustic characterization of the theatre, as shown both through on-site measurements during the main construction phases and through numerical simulati…
Reverberation still in business: Thickening and propagating micro-textures in physics-based sound modeling
2015
Artificial reverberation is usually introduced, as a digital audio effect, to give a sense of enclosing architectural space. In this paper we argue about the effectiveness and usefulness of diffusive reverberators in physically-inspired sound synthesis. Examples are given for the synthesis of textural sounds, as they emerge from solid mechanical interactions, as well as from aerodynamic and liquid phenomena.