New hearing threshold measurements for pure tones under free-field listening conditions

Annoyance of low frequency pure and combined tones was measured in a laboratory experiment. Three low frequency tones at frequencies of 31.5, 50 and 80 Hz at four sound pressure levels, from about 6 dB to 24 dB above average hearing threshold, were selected as pure tones. The combined tones were combinations of two tones: the four levels of 31.5, 50 and 80 Hz tones and a constant level 40 Hz tone. The results showed that the rate of increase in annoyance of pure tones with increase in the sound pressure level was higher at lower frequencies, as reported in previous studies. The results for the combined tones showed that the increase in the annoyance of the combined tone compared to the annoyance of pure tone was dependent on the level difference of the two tones and their frequency separation. These results were compared with the evaluation obtained from different objective methods. The three methods were Moore's loudness model, the low frequency A-weighting and the total energy summation used as objective evaluation methods. Among the methods, the low frequency A-weighting gave the best correlation.

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Percentiles of normal hearing-threshold distribution under free-field listening conditions in numerical form

Acoustical Science and Technology ◽

10.1250/ast.26.447 ◽

2005 ◽

Vol 26 (5) ◽

pp. 447-449 ◽

Cited By ~ 4

Author(s):

Kenji Kurakata ◽

Tazu Mizunami ◽

Kazuma Matsushita

Keyword(s):

Free Field ◽

Hearing Threshold ◽

Normal Hearing ◽

Threshold Distribution

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Audiological Performance of ADHEAR Systems in Simulated Conductive Hearing Loss: A Case Series with a Review of the Existing Literature

Audiology Research ◽

10.3390/audiolres11040048 ◽

2021 ◽

Vol 11 (4) ◽

pp. 537-546

Author(s):

Enrico Muzzi ◽

Valeria Gambacorta ◽

Ruggero Lapenna ◽

Giulia Pizzamiglio ◽

Sara Ghiselli ◽

...

Keyword(s):

Hearing Loss ◽

Conductive Hearing Loss ◽

Bone Conduction ◽

Free Field ◽

Hearing Threshold ◽

Case Series ◽

Binaural Hearing ◽

Bone Conduction Implant ◽

Conductive Hearing ◽

Loudness Summation

A new non-invasive adhesive bone conduction hearing device (ABCD) has been proposed as an alternative solution for reversible bilateral conductive hearing loss in recurrent or long-lasting forms of otitis media with effusion (OME) in children that cannot undergo surgical treatment. Our aim was to assess the effectiveness of ABCD in children with OME. Twelve normal-hearing Italian-speaking volunteers, in whom a conductive hearing loss was simulated, participated in the study. The free-field average hearing threshold was determined and, to evaluate binaural hearing skills, loudness summation and the squelch effect were assessed. Five conditions were tested: (1) unaided without earplugs, (2) unaided with bilateral earplugs, (3) aided right ear with bilateral earplugs, (4) aided left ear with bilateral earplugs, and (5) bilateral aid with bilateral earplugs. Post-hoc analysis showed a significant statistical difference between plugged, unplugged, and each aided condition. The main results were a better loudness summation and a substantial improvement of the squelch effect in the bilaterally aided. Our results suggest that ABCD is a valid treatment for patients with conductive hearing loss that cannot undergo bone conduction implant surgery. It is also important to consider bilateral aids in order to deal with situations in which binaural hearing is fundamental.

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A free field room for measuring pure tones

The Journal of the Acoustical Society of America ◽

10.1121/1.385967 ◽

1981 ◽

Vol 69 (S1) ◽

pp. S9-S9

Author(s):

O. L. Angevine ◽

E. N. Angevine

Keyword(s):

Free Field ◽

Pure Tones

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Frequency and amplitude representations in anterior primary auditory cortex of the mustached bat

Journal of Neurophysiology ◽

10.1152/jn.1983.50.5.1182 ◽

1983 ◽

Vol 50 (5) ◽

pp. 1182-1196 ◽

Cited By ~ 24

Author(s):

A. Asanuma ◽

D. Wong ◽

N. Suga

Keyword(s):

Auditory Cortex ◽

Second Harmonic ◽

Free Field ◽

Primary Auditory Cortex ◽

Frequency Component ◽

Constant Frequency ◽

Mustached Bat ◽

Pteronotus Parnellii ◽

Frequency Representation ◽

Pure Tones

The orientation sound emitted by the Panamanian mustached bat, Pteronotus parnellii rubiginosus, consists of four harmonics. The third harmonic is 6-12 dB weaker than the predominant second harmonic and consists of a long constant-frequency component (CF3) at about 92 kHz and a short frequency-modulated component (FM3) sweeping from about 92 to 74 kHz. Our primary aim is to examine how CF3 and FM3 are represented in a region of the primary auditory cortex anterior to the Doppler-shifted constant-frequency (DSCF) area. Extracellular recordings of neuronal responses from the unanesthetized animal were obtained during free-field stimulation of the ears with pure tones. FM sounds, and signals simulating their orientation sounds and echoes. Response properties of neurons and tonotopic and amplitopic representations were examined in the primary and the anteroventral nonprimary auditory cortex. In the anterior primary auditory cortex, neurons responded strongly to single pure tones but showed no facilitative responses to paired stimuli. Neurons with best frequencies from 110 to 90 kHz were tonotopically organized rostrocaudally, with higher frequencies located more rostrally. Neurons tuned to 92-94 kHz were overpresented, whereas neurons tuned to sound between 64 and 91 kHz were rarely found. Consequently a striking discontinuity in frequency representation from 91 to 64 kHz was found across the anterior DSCF border. Most neurons exhibited monotonic impulse-count functions and responded maximally to sound pressure level (SPL). There were also neurons that responded best to weak sounds but unlike the DSCF area, amplitopic representation was not found. Thus, the DSCF area is quite unique not only in its extensive representation of frequencies in the second harmonic CF component but also in its amplitopic representation. The anteroventral nonprimary auditory cortex consisted of neurons broadly tuned to pure tones between 88 and 99 kHz. Neither tonotopic nor amplitopic representation was observed. Caudal to this area and near the anteroventral border of the DSCF area, a small cluster of FM-FM neurons sensitive to particular echo delays was identified. The responses of these neurons fluctuated significantly during repetitive stimulation.

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On the Effect of Bimodal Rehabilitation in Asymmetric Hearing Loss

Journal of Clinical Medicine ◽

10.3390/jcm10173927 ◽

2021 ◽

Vol 10 (17) ◽

pp. 3927

Author(s):

Simonetta Monini ◽

Chiara Filippi ◽

Alessandra De Luca ◽

Gerardo Salerno ◽

Maurizio Barbara

Keyword(s):

Hearing Loss ◽

Hearing Aid ◽

Free Field ◽

Hearing Threshold ◽

Beneficial Effects ◽

Auditory Performance ◽

Contralateral Ear ◽

Single Sided Deafness ◽

Asymmetric Hearing Loss

Background: Bone conductive implants (BCI) have been reported to provide greater beneficial effects for the auditory and perceptual functions of the contralateral ear in patients presenting with asymmetric hearing loss (AHL) compared to those with single-sided deafness (SSD). The aim of the study was to assess the effects of wearing a conventional hearing aid in the contralateral ear on BCI in terms of an improved overall auditory performance. Methods: eleven AHL subjects wearing a BCI in their worse hearing ear underwent an auditory evaluation by pure tone and speech audiometry in free field. This study group was obtained by adding to the AHL patients those SSD subjects that, during the follow-up, showed deterioration of the hearing threshold of the contralateral ear, thus presenting with the features of AHL. Four different conditions were tested and compared: unaided, with BCI only, with contralateral hearing aid (CHA) only and with BCI combined with CHA. Results: all of the prosthetic conditions caused a significant improvement with respect to the unaided condition. When a CHA was adopted, its combination with the BCI showed significantly better auditory performances than those achieved with the BCI only. Conclusions: the present study suggests the beneficial role of a CHA in BCI-implanted AHL subjects in terms of overall auditory performance.

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The Effect of Altitude on Absolute Hearing Threshold Levels

Proceedings of the Human Factors Society Annual Meeting ◽

10.1177/154193128202600524 ◽

1982 ◽

Vol 26 (5) ◽

pp. 488-492

Author(s):

I. B. Mekjavic ◽

D. Sinclair ◽

D. Steele ◽

N. S. Longridge

Keyword(s):

Ambient Pressure ◽

Hearing Threshold ◽

Experimental Conditions ◽

Exposure Test ◽

Threshold Levels ◽

Hearing Thresholds ◽

Insignificant Difference ◽

The Mean ◽

Pure Tones ◽

The One

The present study investigates the effect of hypobaric environments on absolute hearing thresholds for pure tones at octave frequencies between 250 Hz and 8 kHz. Absolute hearing thresholds were obtained for ten subjects at ambient pressure (732 mmHg) and at an altitude of 6500 feet (582 mmHg), relative to the laboratory. Subjects were decompressed in a hypobaric chamber at a rate of 500 ft./min. and were subjected to the low pressure environment for one hour before being compressed to a normobaric environment, at a rate of 300 ft./min. Absolute hearing threshold levels obtained at altitude, after the one hour exposure to the hypobaric ambient and on descent to normobaric conditions, were compared with scores obtained prior to the hypobaric exposure. In order to compare the frequency averaged threshold shifts at octave frequencies of 250 Hz, 500 Hz and 1 kHz, for the altitude and normobaric conditions, the audiometer was calibrated at ambient pressures of 732, 582 and 512 mmHg. The results of the study indicate a slight increase in sensitivity of the audiometer headphones with altitude and an insignificant difference between the mean frequency averaged threshold shifts for the pre-exposure test and the three experimental conditions (at the onset of hypobaria, after a one hour exposure to the altitude and on descent to surface).

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