The Sound Field Around a Tuning Fork and the Role of a Resonance Box

2015 ◽  
Vol 53 (2) ◽  
pp. 97-100 ◽  
Author(s):  
Bogdan F. Bogacz ◽  
Antoni T. Pędziwiatr
Keyword(s):  
Tuning Fork ◽  
Sound Field

scholarly journals Contralateral Occlusion Test (COT): the effect of external ear canal occlusion with aging

CoDAS ◽  
2019 ◽  
Vol 31 (3) ◽  
Author(s):  
Luís Roque Reis ◽  
Luís Castelhano ◽  
Filipe Correia ◽  
Pedro Escada
Keyword(s):  
Hearing Loss ◽  
Tuning Fork ◽  
Age Groups ◽  
Sound Field ◽  
External Ear ◽  
Ear Canal ◽  
Occlusion Test ◽  
External Ear Canal ◽  
Hearing Thresholds ◽  
And Gender

ABSTRACT Purpose This study aimed to evaluate the effects of complete external ear canal occlusion on hearing thresholds with aging. The goal was to decide which tuning fork is more appropriate to use for the contralateral occlusion test (COT), in individuals of different ages. Methods Forty-two normal hearing subjects between 21 and 67 years were divided into three age groups (20-30 years, 40-50 years, and 60-70 years). Participants underwent sound field audiometry tests with warble tones, with and without ear canal occlusion. Each ear was tested with the standard frequencies (250, 500, 1000, and 2000 Hz). The contralateral ear was suppressed by masking. Results Hearing thresholds showed an increase as the frequency increased from 20.85 dB (250 Hz, 20-30 years group) to 48 dB (2000 Hz, 60-70 years group). The threshold differences between occlusion and no occlusion conditions were statistically significant and increased ranging from 11.1 dB (250 Hz, 20-30 years group) to 32 dB (2000 Hz, 20-30 years group). We found statistically significant differences for the three age groups and for all evaluations except to 500 Hz difference and average difference. The mean hearing loss produced by occlusion at 500 Hz was approximately 19 dB. We found no statistically significant differences between right and left ears and gender for all measurements. Conclusion We conclude that the use of the 512 Hz tuning fork is the most suitable for COT, and its use may allow clinicians to distinguish mild from moderate unilateral conductive hearing loss.

On the Acoustics of Auditoria

1994 ◽  
Vol 1 (1) ◽  
pp. 27-48 ◽  
Author(s):  
H. Kuttruff
Keyword(s):  
Sound Propagation ◽  
Sound Field ◽  
Great Benefit ◽  
Room Acoustics ◽  
Short Introduction ◽  
New Developments ◽  
Sound Fields ◽  
Field Simulation ◽  
Basic Facts

The paper presents a short introduction into auditorium acoustics and reports on a few new developments in this field, which are believed to be of great benefit both for the acoustical design of auditoria and for research in practical room acoustics. The first part describes in a rather elementary way the basic facts of sound propagation in enclosures, including the effects of reflections and the role of reverberation. Furthermore, some of the numerous objective parameters are discussed which have been introduced in order to characterize particular aspects of sound fields. In the second part, recently developed methods of sound field simulation are described by which such parameters can be predicted. Methods of “auralization” are briefly discussed by which aural impressions from non-existing halls can be created on the basis of digital sound field simulation.

Study on the Influence of Volute to Flow-Induced Noise in Centrifugal Pump

2012 ◽  
Vol 516-517 ◽  
pp. 1009-1017 ◽  
Author(s):  
Qiao Rui Si ◽  
Shou Qi Yuan ◽  
Jian Ping Yuan ◽  
Chuan Wang ◽  
Jun Yang
Keyword(s):  
Centrifugal Pump ◽  
Transmission Loss ◽  
Incidence Angle ◽  
Sound Transmission ◽  
Sound Field ◽  
Acoustic Coupling ◽  
Flow Induced Noise ◽  
Structure Vibration ◽  
Full Reflection

More and more attention has been attached on flow-induced noise of centrifugal pump in recent years because of strict environmental noise restrictions and demands of clients.. In this paper, the role of volute impacted on flow-induced noise generation and propagation in centrifugal pump were summarized. The process of internal wave propagation was analyzed, and the transmission coefficient and loss of volute were calculated; In order to compare the effect of volute vibration on the sound field in a centrifugal pump, a hybrid algorithm based on CFD + BEM was adopted. The results reveals that: full reflection of sound wave occurs on the fluid-steel volute wall when the incidence angle is more than or equal to 13.8 °; otherwise a sound transmission appears; For onshore pumps, For onshore pumps the A-weighted sound transmission loss is more than 55dB under the condition that thickness volute is not less than 8mm; For submersible pumps, all-bottom sound below 3000Hz almost transmits to the outside field entirely; structure acoustic coupling between volute and the internal sound field influence little on directivity of sound field and the change of law, but structure vibration would average the sound pressure level in frequency.

Life in the epoch of changes: realities and prospects. School Principal's Outlook Potential

2020 ◽  
pp. 18-23
Author(s):  
V. P. Andrushchenko
Keyword(s):  
Tuning Fork ◽  
Social Experience ◽  
The State ◽  
Educational Process ◽  
Unique Role ◽  
Whole School ◽  
University Studies ◽  
The World

The academic and social experience accumulated over the years and decades of our society’s activity demonstrates the unique role of the headmaster as the first and principal organizer of the educational process, the teacher of the student youth, the parents and all employees of the institution. And that’s understandable. The headmaster is a person who the whole team is based on, who they follow and whose activity, as a tuning fork, sets the tone of the work of the whole school. He is not only the organizer of the educational process or the head of the business, but also the first teacher-advisor of the team. He is fully responsible for the state of work of the school as a whole, and most importantly – for the civic, spiritual, moral, patriotic charge with which teachers approach their pupils, and they, in turn, assimilate it and go into the world as independent and creative personalities. It is he who – confident, convinced, creative – conveys to the team his own worldview potential, accumulated in his time during his university studies, as well as in the process of gaining practical academic and civic experience. Therefore, it is quite understandable the need for a high ideological training of the director, the formation and constant updating of his political, spiritual, moral, aesthetic, etc. culture in general.

On the sound field radiated by a tuning fork

2000 ◽  
Vol 68 (12) ◽  
pp. 1139-1145 ◽  
Author(s):  
Daniel A. Russell
Keyword(s):  
Tuning Fork ◽  
Sound Field

scholarly journals On the Pushkin text in the poetry of Perestroika

2020 ◽  
Vol 11 (2) ◽  
pp. 80-95
Author(s):  
Olga I. Severskaya
Keyword(s):  
Tuning Fork ◽  
Common Noun ◽  
Cultural Codes ◽  
Single Text ◽  
The World

This article is devoted to Perestroika poets referring to the Pushkin text as a ‘tuning fork’ in reconfiguring poetics. The study aims to show that, in this case, intertextual connection create a special text-within-a-text. The corpus, intertextual, and compositional methods are used to analyse Pushkin-invoking texts by Yuri Arabov, Vladimir Druk, Timur Kibirov, and other poets. It is concluded that these authors perceive Pushkin’s poetry as a lexicon whose units can be used for building countless cycles of poetic reflections on the world as well as on poetry and the role of the poet. The donor text is an interlinear gloss for the recipient text. The implicit ‘alien’ and the explicit ‘own’ words merge into a single text. Perestroika poets inherit from Pushkin polystylism, a propensity to parody when analysing cultural codes and prece­dent texts, and fundamental dialogicity. Particular attention is paid to variations on the theme of Pushkin's ‘Monument’ as well as the symbolism of his name, which turned into somewhat of a common noun used to refer to any poet. The predominance of allusions to quotes in references to Pushkin points to the desire of perestroika poets engage in an equal dialogue with the national genius. At the same time, the Pushkin text becomes for them the point at which the semantic perspective of both a concrete poetic utterance and poetry as a whole is refracted.

Clinical role of informal tests of hearing

1989 ◽  
Vol 103 (1) ◽  
pp. 7-11 ◽  
Author(s):  
G. G. Browning ◽  
I. R. C. Swan ◽  
K. K. Chew
Keyword(s):  
Pure Tone ◽  
Tuning Fork ◽  
Bone Conduction ◽  
Free Field ◽  
Pure Tone Audiometry ◽  
Comparison Method ◽  
Clinical Tests ◽  
Clinical Role ◽  
Modern Methods

AbstractClinical tests of hearing are regularly used in adults but their role, now that pure-tone audiometry is almost universally available, has not been evaluated by modern methods of analysis including sensitivity and specificity.Free-field voice testing was carried out in 101 patients and the Rinne tuning-fork test in a different group of 127 patients prior to clinical or audiometric evaluation. The results were subsequently compared to air and bone conduction pure-tone thresholds assessed using rigorous standards.Depending on the audiometric definition as to what constitutes a hearing impairment, the sensitivity of free-field voice testing to identify such an impairment because of an inability to hear a whispered voice at two feet (60 cm.) was 86 per cent or better with the specificity being in the region of 90 per cent.In the Rinne test the 256 Hz fork was superior to the 512 Hz fork (p<0.05) and the loudness comparison method superior to the threshold decay method (p<0.01) in detecting an air-bone gap. Combining the responses to the two forks did not improve the results. The Rinne test with the 256 Hz fork will identify correctly 48 per cent of individuals with a 15 dB, 69 per cent with a 20 dB, 87 per cent with a 25 dB, and 95 per cent with a 30 dB conductive impairment. In all instances the specificity is greater than 90 per cent.

Tympanal hearing in the sarcophagid parasitoid fly Emblemasoma sp.: the biomechanics of directional hearing

1999 ◽  
Vol 202 (14) ◽  
pp. 1865-1876 ◽  
Author(s):  
D. Robert ◽  
R.N. Miles ◽  
R.R. Hoy
Keyword(s):  
Mechanical Response ◽  
Sound Field ◽  
Striking Difference ◽  
Directional Hearing ◽  
Vibrational Modes ◽  
Acoustic Detection ◽  
Sense Organs ◽  
Auditory Systems ◽  
Detection And Localization

In Diptera, tympanal hearing has evolved at least twice in flies that belong to two different families, the tachinids and the sarcophagids. Common to these flies is their parasitoid reproductive strategy, both relying on the acoustic detection and localization of their hosts, singing insects, by means of tympanal hearing organs. In the present study, the external anatomy of the unusual hearing organs of the sarcophagid fly Emblemasoma sp. is described. The sarcophagid ears bear numerous anatomical similarities with those of ormiine tachinids: they are located on the ventral prosternum and possess a pair of scolopidial mechanoreceptive sense organs. A striking difference, however, resides in the lack of a well-defined presternum in the sarcophagid tympanal system. Instead, a deep longitudinal fold, the tympanal fold, spans both hemilateral tympanal membranes across the midline of the animal. Measured using laser Doppler vibrometry, the tympanal mechanical response in the sound field reveals asymmetrical deflection shapes that differ from those of tachinids. Lacking a central fulcrum, the sarcophagid tympanal complex presents different vibrational modes that also result in interaural coupling. The evolutionarily convergent, yet distinct, solutions used by these two small auditory systems to extract directional cues from the sound field and the role of tympanal coupling in this process are discussed.

Sign in / Sign up

Export Citation Format

Share Document