scholarly journals Sound Synthesis with Auditory Distortion Products

2014 ◽  
Vol 38 (4) ◽  
pp. 5-23 ◽  
Author(s):  
Gary S. Kendall ◽  
Christopher Haworth ◽  
Rodrigo F. Cádiz
Keyword(s):  
Otoacoustic Emissions ◽  
Dynamic Properties ◽  
Sound Synthesis ◽  
Synthesis Methods ◽  
Distortion Products ◽  
Single Sideband ◽  
Target Spectrum ◽  
Difference Tones ◽  
Rich History ◽  
Very High

This article describes methods of sound synthesis based on auditory distortion products, often called combination tones. In 1856, Helmholtz was the first to identify sum and difference tones as products of auditory distortion. Today this phenomenon is well studied in the context of otoacoustic emissions, and the “distortion” is understood as a product of what is termed the cochlear amplifier. These tones have had a rich history in the music of improvisers and drone artists. Until now, the use of distortion tones in technological music has largely been rudimentary and dependent on very high amplitudes in order for the distortion products to be heard by audiences. Discussed here are synthesis methods to render these tones more easily audible and lend them the dynamic properties of traditional acoustic sound, thus making auditory distortion a practical domain for sound synthesis. An adaptation of single-sideband synthesis is particularly effective for capturing the dynamic properties of audio inputs in real time. Also presented is an analytic solution for matching up to four harmonics of a target spectrum. Most interestingly, the spatial imagery produced by these techniques is very distinctive, and over loudspeakers the normal assumptions of spatial hearing do not apply. Audio examples are provided that illustrate the discussion.

Response Prediction and Dynamic Substructuring for Coupled Structures in the Frequency Domain

2020 ◽  
Vol 36 (6) ◽  
pp. 867-879
Author(s):  
X. H. Liao ◽  
W. F. Wu ◽  
H. D. Meng ◽  
J. B. Zhao
Keyword(s):  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Dynamic Properties ◽  
Main Idea ◽  
Prediction Method ◽  
Response Prediction ◽  
Synthesis Methods ◽  
Dynamic Substructuring ◽  
Coupled Structures

ABSTRACTTo evaluate the dynamic properties of a coupled structure based on the dynamic properties of its substructures, this paper investigates the dynamic substructuring issue from the perspective of response prediction. The main idea is that the connecting forces at the interface of substructures can be expressed by the unknown coupled structural responses, and the responses can be solved rather easily. Not only rigidly coupled structures but also resiliently coupled structures are investigated. In order to further comprehend and visualize the nature of coupling problems, the Neumann series expansion for a matrix describing the relation between the coupled and uncoupled substructures is also introduced in this paper. Compared with existing response prediction methods, the proposed method does not have to measure any forces, which makes it easier to apply than the others. Clearly, the frequency response function matrix of coupled structures can be derived directly based on the response prediction method. Compared with existing frequency response function synthesis methods, it is more straightforward and comprehensible. Through demonstration of two examples, it is concluded that the proposed method can deal with structural coupling problems very well.

DPOAE-Grams in Patients with Acute Tonal Tinnitus

2005 ◽  
Vol 132 (4) ◽  
pp. 550-553 ◽  
Author(s):  
Haralampos Gouveris ◽  
Jan Maurer ◽  
Wolf Mann
Keyword(s):  
Otoacoustic Emissions ◽  
Outer Hair Cell ◽  
Cell Function ◽  
Hearing Threshold ◽  
Normal Hearing ◽  
Outer Hair Cells ◽  
Controlled Study ◽  
High Frequency Region ◽  
Mean Values ◽  
Distortion Products

OBJECTIVE: To investigate cochlear outer hair cell function in patients with acute tonal tinnitus and normal or near-normal hearing threshold. STUDY DESIGN AND SETTING: Prospective controlled study in an academic tertiary health center. Distortion products of otoacoustic emissions (DPOAE)-grams of 32 ears with acute tonal tinnitus and normal hearing or minimal hearing loss were compared with those of 17 healthy nontinnitus ears. RESULTS: Tinnitus ears exhibited relatively increased amplitudes of DPOAE at high frequencies (4-6.3 kHz) when compared with the group of healthy ears and relatively decreased DPOAE amplitudes at middle frequencies (1650-2400 Hz). Statistically significant ( P < 0.01) increased mean values of DPOAE amplitudes were observed only at a frequency of f2 equal to 4.9 kHz. CONCLUSIONS AND SIGNIFICANCE: These findings suggest an altered functional state of the outer hair cells at a selected high-frequency region of the cochlea in ears with acute tonal tinnitus and normal or near-normal hearing threshold.

Sound synthesis methods of fire flame sound for predicting hidden images

2016 ◽  
Vol 139 (4) ◽  
pp. 1986-1986
Author(s):  
HyunIn Jo ◽  
Rehan H. Afzal ◽  
Imran Muhammad ◽  
Jin Y. Jeon
Keyword(s):  
Sound Synthesis ◽  
Synthesis Methods ◽  
Fire Flame

Stress-Strain Testing of Rubber at High Rates of Elongation

1963 ◽  
Vol 36 (1) ◽  
pp. 28-49
Author(s):  
Mark L. Dannis
Keyword(s):  
Tensile Strength ◽  
Time Scale ◽  
High Speed ◽  
Dynamic Properties ◽  
Stress Strain ◽  
High Frequencies ◽  
Apparent Modulus ◽  
Strain Testing ◽  
Considerable Body ◽  
Very High

Abstract It is well known that the properties of rubbery materials depend upon the speed or rate at which they are tested or used. A considerable body of work has shown that the dynamic properties of rubber change with the time scale of the test and, in particular, at very short times or at very fast rates, the properties approach those of plastics, i.e., high modulus and low elongation. These dynamic properties are measured by oscillation methods, usually at small strains. In contrast to this class of information, where the material is rarely strained to failure, one can also strain rubbers unidirectionally to failure at strain rates that correspond to the high frequencies of dynamic measurements. In linear extension experiments, as the rate of stretching increases tensile strength rises, elongation drops, apparent modulus increases, and relaxation losses may go up or down depending upon the particular rubber and the time scale of the phenomenon that is being investigated. Extrapolating the change in tensile strength with rate of testing suggests that tensile strength as we know it should change drastically when measured at very high rates of speed. That is, since the viscoelastic properties of rubber are time dependent, and also dependent upon the speed at which they are tested, the tensile properties of rubbers measured at room conditions with the ordinary Scott or Instron machines probably do not have the same values as at the speeds and frequencies that might be encountered in such situations as tire wear. Hence, we should like to measure the properties of rubbers at very high rates of speed, presumably comparable to those encountered in tire tread wear, in order to find out how much properties do change as the speed of test is increased. In order to measure stress-strain properties at rates of elongation comparable to those we believe exist in tire tread usage, we had to develop a small high speed tensile machine. The purpose of this paper is to describe that machine and some results obtained with it.

Hearing impairment among workers occupationally exposed to excessive levels of noise

Open Medicine ◽  
2007 ◽  
Vol 2 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Pavlina Gidikova ◽  
Gospodinka Prakova ◽  
Petar Ruev ◽  
Gergana Sandeva
Keyword(s):  
Hearing Loss ◽  
Hearing Impairment ◽  
Otoacoustic Emissions ◽  
Gradual Increase ◽  
Pure Tone Audiometry ◽  
Noise Levels ◽  
Distortion Products ◽  
Occupationally Exposed ◽  
Intermittent Noise ◽  
Excessive Noise

AbstractPure tone audiometry screening and ear examinations were conducted among 138 males working as machine and equipment operators occupationally exposed to intermittent noise of 85 to 105 dBA. Hearing loss up to 30 dB (preserved socially adequate hearing) was found in 25 workers. The hearing impairment was confirmed by distortion products of otoacoustic emissions measurements. A sharp increase in the frequency of cases can be found among the workers with service length over 10 years. While the frequency of the cases among workers with service length below 10 years is 5.45%, it is 26.5% among the subjects with service length over 10 years, with a gradual increase as a result of the increase in exposure duration. A positive correlation (p < 0.05) was found between the frequency of hearing impairment among the workers and the years of exposure to excessive noise levels. Some measures for preventing occupational noise-induced hearing loss were suggested.

scholarly journals Using electrocochleography to detect sensory and neural damages in a gerbil model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sebastiaan W. F. Meenderink ◽  
Xiaohui Lin ◽  
Wei Dong
Keyword(s):  
Otoacoustic Emissions ◽  
Round Window ◽  
Auditory Pathway ◽  
Distortion Product Otoacoustic Emissions ◽  
Treatment Intervention ◽  
Distortion Product ◽  
Neural Damage ◽  
Distortion Products ◽  
Appropriate Treatment ◽  
Distinct Level

AbstractHearing is one of the five sensory organs that allows us to interact with society and our environment. However, one in eight Americans suffers from sensorineural hearing loss that is great enough to adversely impact their daily life. There is an urgent need to identify what part/degree of the auditory pathway (sensory or neural) is compromised so that appropriate treatment/intervention can be implemented. Single- or two-tone evoked potentials, the electrocochleography (eCochG), were measured along the auditory pathway, i.e., at the round window and remotely at the vertex, with simultaneous recordings of ear canal distortion product otoacoustic emissions. Sensory (cochlear) and neural components in the (remote-) eCochG responses showed distinct level- and frequency-dependent features allowing to be differentiated from each other. Specifically, the distortion products in the (remote-)eCochGs can precisely localize the sensory damage showing that they are effective to determine the sensory or neural damage along the auditory pathway.

Effect of Tinnitus in Distortion Products Otoacoustic Emissions (DPOAEs) in Normal Hearing Patients

2021 ◽  
Author(s):  
Leticia Acle-Cervera ◽  
Javier Gavilanes-Plasencia ◽  
Beatriz Delgado-Vargas ◽  
Lorena Sánz-López ◽  
Mireya Bonet-Loscertales ◽  
...  
Keyword(s):  
Otoacoustic Emissions ◽  
Normal Hearing ◽  
Distortion Products
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