The role of excitation on modifying the sound sources

1984 ◽  
Author(s):  
R. MANKBADI
Keyword(s):  
Sound Sources

scholarly journals The Historical Soundscape Analysis of Fatahillah Square, Jakarta

Acoustics ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 847-867
Author(s):  
Michael Isnaeni Djimantoro ◽  
Widjaja Martokusumo ◽  
Heru W. Poerbo ◽  
R. Joko Sarwono
Keyword(s):  
Cultural Heritage ◽  
Visual Analysis ◽  
Sound Sources ◽  
The Past ◽  
Holistic Understanding ◽  
Sonic Environment ◽  
The 19Th Century ◽  
Comprehensive Study

Understanding conceptions of the protection of cultural heritage continues to develop until now. Presently, urban historic places are not only comprehended as tangible but also include intangible dimensions. However, the conservation of cultural heritage dominantly still emphasises the visual sense more than any other senses. Thus, this paper addressed several questions on the role of human senses, the historic sonic environments, and the soundmarks of the past in examining a historical area. This paper aims to reveal the relation between sound sources and its predicted sonic environment in historic places over the time. The case study was Fatahillah Square, Jakarta, which has been documented from the 19th century until now. Some methods were carried out such as soundwalk, recalled in memory, and visual analysis. The results show that comprehensive study of multisensorial stimulus can increase a holistic understanding of historic places. Therefore, the protection of historic sites cannot only focus on the object per se, but also it must be considered to be a holistic entity. This research highlights new perspectives in analysing historical areas using combination of pictorial sources and sonic information.

scholarly journals The Role of Reverberation and Magnitude Spectra of Direct Parts in Contralateral and Ipsilateral Ear Signals on Perceived Externalization

2019 ◽  
Vol 9 (3) ◽  
pp. 460 ◽  
Author(s):  
Song Li ◽  
Roman Schlieper ◽  
Jürgen Peissig
Keyword(s):  
Speech Signal ◽  
Impulse Responses ◽  
Sound Sources ◽  
Reverberant Environments ◽  
Contralateral Ear ◽  
Listening Experiment ◽  
Binaural Sound

Several studies show that the reverberation and spectral details in direct sounds are two essential cues for perceived externalization of virtual sound sources in reverberant environments. The present study investigated the role of these two cues in contralateral and ipsilateral ear signals on perceived externalization of headphone-reproduced binaural sound images at different azimuth angles. For this purpose, seven pairs of non-individual binaural room impulse responses (BRIRs) were measured at azimuth angles of −90°, −60°, −30°, 0°, 30°, 60°, and 90° in a listening room. The magnitude spectra of direct parts were smoothed, and the reverberation was removed, either in left or right ear BRIRs. Such modified BRIRs were convolved with a speech signal, and the resulting binaural sounds were presented over headphones. Subjects were asked to assess the degree of perceived externalization for the presented stimuli. The result of the subjective listening experiment revealed that the magnitude spectra of direct parts in ipsilateral ear signals and the reverberation in contralateral ear signals are important for perceived externalization of virtual lateral sound sources.

Locating two sound sources: The role of amplitude modulation and spectral content.

2011 ◽  
Vol 129 (4) ◽  
pp. 2488-2488
Author(s):  
Willim A. Yost ◽  
Christopher Brown ◽  
Farris Walling
Keyword(s):  
Amplitude Modulation ◽  
Sound Sources ◽  
Spectral Content

The object of perception in impacted sound sources: The role of perceptual accessibility and information accuracy

2007 ◽  
Vol 121 (5) ◽  
pp. 3166-3166 ◽  
Author(s):  
Bruno L. Giordano ◽  
Stephen McAdams ◽  
Davide Rocchesso
Keyword(s):  
Sound Sources

Jazz Drums

2019 ◽  
pp. 219-230
Author(s):  
Gregory Evans
Keyword(s):  
Music Educators ◽  
Drum Set ◽  
Sound Sources

It is no secret that music educators are faced with unique challenges when engaging young musicians who play drum sets. Many educators aren’t drummers themselves, which can create fear and uncertainty and ultimately lead them to avoid, rather than embrace, the wonderful and exciting world of jazz percussion. This chapter provides conceptual and technical approaches to understanding the role each component of the drum set contributes to the ensemble, as well as the role of the drum set in its entirety. It also touches on how dynamics can change the function and style of a groove as well as creative ways to encourage students to move beyond pattern playing. In particular, discussion and examples are provided regarding setup, sound sources, keeping time, functioning within the rhythm section, transitioning from timekeeping to improvising, and various rhythms and grooves.

The Role of Mechanical Reproduction in (What Was Formerly Known as) the Record in the Age of Personal Fabrication

2014 ◽  
Vol 24 ◽  
pp. 65-67 ◽  
Author(s):  
Kazuhiro Jo
Keyword(s):  
Production Technique ◽  
Sound Sources ◽  
Mechanical Reproduction ◽  
The Creation ◽  
Recent Project ◽  
A Performance

The author examines the role of mechanical reproduction in (what was formerly known as) analog records in the age of personal fabrication with an example from his recent project cutting record. He investigates the creation of records without inputting sound sources by utilizing a production technique and a variety of materials, in conjunction with a discussion of a performance and workshop extracted from the project.

scholarly journals The role of envelope shape in the localization of multiple sound sources and echoes in the barn owl

2013 ◽  
Vol 109 (4) ◽  
pp. 924-931 ◽  
Author(s):  
Caitlin S. Baxter ◽  
Brian S. Nelson ◽  
Terry T. Takahashi
Keyword(s):  
Sound Localization ◽  
Precedence Effect ◽  
Tyto Alba ◽  
Topographic Map ◽  
Sound Sources ◽  
Auditory Space ◽  
Amplitude Spectra ◽  
Barn Owls ◽  
The One

Echoes and sounds of independent origin often obscure sounds of interest, but echoes can go undetected under natural listening conditions, a perception called the precedence effect. How does the auditory system distinguish between echoes and independent sources? To investigate, we presented two broadband noises to barn owls ( Tyto alba) while varying the similarity of the sounds' envelopes. The carriers of the noises were identical except for a 2- or 3-ms delay. Their onsets and offsets were also synchronized. In owls, sound localization is guided by neural activity on a topographic map of auditory space. When there are two sources concomitantly emitting sounds with overlapping amplitude spectra, space map neurons discharge when the stimulus in their receptive field is louder than the one outside it and when the averaged amplitudes of both sounds are rising. A model incorporating these features calculated the strengths of the two sources' representations on the map (B. S. Nelson and T. T. Takahashi; Neuron 67: 643–655, 2010). The target localized by the owls could be predicted from the model's output. The model also explained why the echo is not localized at short delays: when envelopes are similar, peaks in the leading sound mask corresponding peaks in the echo, weakening the echo's space map representation. When the envelopes are dissimilar, there are few or no corresponding peaks, and the owl localizes whichever source is predicted by the model to be less masked. Thus the precedence effect in the owl is a by-product of a mechanism for representing multiple sound sources on its map.

scholarly journals The role of spectral composition of sounds on the localization of sound sources by cats

2013 ◽  
Vol 109 (6) ◽  
pp. 1658-1668 ◽  
Author(s):  
Daniel J. Tollin ◽  
Janet L. Ruhland ◽  
Tom C. T. Yin
Keyword(s):  
Sound Localization ◽  
Spectral Composition ◽  
Power Spectra ◽  
Sound Sources ◽  
Gaze Shift ◽  
Localization Accuracy ◽  
Low Pass ◽  
Localization Performance ◽  
High Pass

Sound localization along the azimuthal dimension depends on interaural time and level disparities, whereas localization in elevation depends on broadband power spectra resulting from the filtering properties of the head and pinnae. We trained cats with their heads unrestrained, using operant conditioning to indicate the apparent locations of sounds via gaze shift. Targets consisted of broadband (BB), high-pass (HP), or low-pass (LP) noise, tones from 0.5 to 14 kHz, and 1/6 octave narrow-band (NB) noise with center frequencies ranging from 6 to 16 kHz. For each sound type, localization performance was summarized by the slope of the regression relating actual gaze shift to desired gaze shift. Overall localization accuracy for BB noise was comparable in azimuth and in elevation but was markedly better in azimuth than in elevation for sounds with limited spectra. Gaze shifts to targets in azimuth were most accurate to BB, less accurate for HP, LP, and NB sounds, and considerably less accurate for tones. In elevation, cats were most accurate in localizing BB, somewhat less accurate to HP, and less yet to LP noise (although still with slopes ∼0.60), but they localized NB noise much worse and were unable to localize tones. Deterioration of localization as bandwidth narrows is consistent with the hypothesis that spectral information is critical for sound localization in elevation. For NB noise or tones in elevation, unlike humans, most cats did not have unique responses at different frequencies, and some appeared to respond with a “default” location at all frequencies.

The Role of Viscosity in Aerodynamic Sound Generation

2003 ◽  
Vol 2 (3) ◽  
pp. 225-240 ◽  
Author(s):  
C.L. Morfey
Keyword(s):  
Green Function ◽  
Plane Boundary ◽  
Shear Stresses ◽  
Normal Velocity ◽  
Acoustic Analogy ◽  
Sound Sources ◽  
Surface Shear ◽  
Boundary Problems ◽  
Aerodynamic Sound

The interpretation of unsteady surface shear stresses as dipole sound sources is discussed. Provided ωv/c2 « 1, it is legitimate to calculate the radiated pressure using viscous surface dipoles in combination with an inviscid-medium Green function. This is demonstrated via comparisons of acoustic-analogy predictions with exact solutions, for two plane-boundary problems. A Green function that is tailored to the linear relation between pressure and normal velocity on the boundary, as used by Powell [ J. Acoust. Soc. Am. Vol. 32, 1960, pp. 982–990], highlights the role of viscous stresses in aeroacoustic calculations.

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