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At least 307 records · Page 17Linked to original sources
PubMed1995

Self-amputation of the ear: three men amputate four ears within five months.

Four instances are presented of self-amputation of the pinna of the external ear carried out by three right-handed, white males between January 1993 and May 1993. The common characteristics of these subjects--two men with personality disorder and one with schizophrenia--are discussed and compared with other examples of self-mutilation involving the face and ears, including that of van Gogh. A survey of Australian and New Zealand prisons was conducted to determine the frequency of this form of self-mutilation within the last five years, and yielded only one other case. Connections exist between the amputees supporting the notion that self-mutilation is "contagious"; the relevance of this to issues of management is considered.

Adolescent↗
PubMed2000

Speech recognition with in-the-ear and behind-the-ear dual-microphone hearing instruments.

The primary purpose of this study was to compare the overall listening benefit in diffuse noise provided by dual-microphone technology in an in-the-ear (ITE) hearing instrument to that provided by dual-microphone technology in a behind-the-ear (BTE) hearing instrument. Further, the study was designed to determine whether the use of the dual-microphone + the manufacturer's party response algorithm in the ITE and BTE hearing instruments provided listening benefit in diffuse noise over their respective omnidirectional microphone modes. Twenty-four adults with mild to moderately severe sensorineural hearing loss were evaluated while wearing binaural BTE and ITE hearing instruments. The results indicated that the dual-microphone + party response mode did provide significant benefit in diffuse noise for both the ITE (3.27 dB signal-to-noise ratio [SNR] improvement) and BTE (5.77 dB SNR improvement) hearing instruments relative to their respective conventional omnidirectional microphones. No significant difference in performance was found between the ITE and BTE hearing instruments when each device was in the dual-microphone + party response mode. It is concluded that the use of dual-microphone technology in both ITE and BTE hearing instruments can improve speech recognition in diffuse noise.

Adult↗
PubMed1992

[Ear ossicle transplants for reconstruction of sound transmission in the middle ear. A histologic long-term study].

In this study 130 ossicular middle ear transplants were studied. 33 remained in the middle ear for 10 years or longer, one for 21 years. The majority of the grafts show 5% to 40% bone new formation. Absence of vital bone or subtotal host bone replacement is exceptional. The amount of bone new formation appears independent the implantation time. 75% of the grafts show no bone resorption. In 15% sound transmitting might be impaired due to resorption. Grafts with a high degree of bone new formation show less resorption. 21% of the ossicles have signs of inflammation. Inflammation boosts bone turnover with resorption on one hand and new for resorption. Cholesteatoma is the main cause of resorption and inflammation. The critical phase for resorption of the graft are the first two to three years after transplantation. No considerable difference was found between autografts and allografts (homografts). Histological and metabolical properties of the ossicles seem to be responsible for the stability of the graft. Ossicular grafts have a good longterm stability which makes them very suitable for reconstruction of the ossicular chain.

Bone Resorption↗
PubMed1989

[Movement of the ear ossicles by middle ear muscle contraction].

Up to now, the function of the middle ear muscles has mainly been investigated from an acoustical point of view. However, the primary function of the middle-ear muscles, namely the induction of ossicular movements, has never been investigated systematically. For this purpose, the displacements of the ossicles, as induced by simulated muscle contractions, were measured microscopically in 13 fresh temporal bone preparations. Both muscles move all ossicles. The tensor tympani muscle pulls the umbo inwards about 100 microns. Due to the gliding motion in the malleus-incus joint, the stapes is thus pushed inwards by at the most 10 microns and, additionally, displaced anteriorly, antagonistic to the pull of the stapedius muscle. This muscle pulls the stapes backwards, lifting the anterior crus outwards and pushing the posterior crus inwards. This reduces the pressure on the cochlear fluids significantly as compared to our former concepts of the movement of the footplate, tilting outwards as a whole around an axis at the posterior pole. Furthermore, this outward displacement of the stapes is not prerequisite for the outward movement of the malleus-drumhead complex, which typically appears at the contraction of the stapedius muscle. The basic motion of the stapes is the movement backwards, which is 5 times greater and which matches the anatomic direction of the pull of the stapedius muscle. This explains the otherwise unlogical position of the stapedius muscle parallel to the footplate. Due to the gliding movement in the malleus-incus joint, this motion changes at the umbo into outward rotation, counteracting the tensor tympani muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Ear Ossicles↗
PubMed1988

[Mechanics of the ear ossicle chain in static pressures. I. The normal middle ear].

The mechanics of the ossicle chain, induced by variations of static air pressure ranging from 0 to +/- 400 H2O, were analysed in an experimental study of 25 temporal bone preparations. The three-dimensional movements of the umbo, the proc. lenticularis and stapes at these pressures, applied at the external ear canal, were measured microscopically. Direct high-grade radiographic magnification technique demonstrated these displacements dynamically. In the normal ossicle chain, the air pressure-induced inward-outward excursions of the malleus are transformed by the gliding incudo-malleal joint, resulting predominantly in an upward and downward movement of the lenticular process. Thus, the incudo-stapedial joint can glide, and the stapes is uncoupled from the extensive displacements of the drum membrane and malleus. This mode of motion accounts for some anatomical details of the middle ear and explains results of former studies of ossicle vibrations produced by unphysiologically high sound pressures.

Adolescent↗
PubMed1986

Comparison of in-the-ear and over-the-ear hearing aid fittings.

A custom in-the-ear (ITE) hearing aid fitting was compared to two over-the-ear (OTE) hearing aid fittings for each of 9 subjects with mild to moderately severe hearing losses. Speech intelligibility via the three instruments was compared using the Speech Intelligibility Rating (SIR) test. The relationship between functional gain and coupler gain was compared for the ITE and the higher rated OTE instruments. The difference in input received at the microphone locations of the two types of hearing aids was measured for 10 different subjects and compared to the functional gain data. It was concluded that (a) for persons with mild to moderately severe hearing losses, appropriately adjusted custom ITE fittings typically yield speech intelligibility that is equal to the better OTE fitting identified in a comparative evaluation; and (b) gain prescriptions for ITE hearing aids should be adjusted to account for the high-frequency emphasis associated with in-the-concha microphone placement.

Acoustics↗
PubMed1991

Maximum real-ear gain of in-the-ear hearing aids.

Three hearing aid manufacturers provided custom full-shell in-the-ear hearing aids for each of 3 hearing-impaired subjects. Each manufacturer was instructed that the hearing aids should provide the maximum possible acoustic gain within the limits of hearing aid shell size and available components. Coupler gain, insertion gain, and functional gain were measured for each hearing aid. Gain measures were made with the volume control at either the full-on setting or the highest setting possible before the onset of acoustical feedback. Full-on coupler gain curves were similar across all nine hearing aids. Individual differences in concha/ear canal size and in the fit of the hearing aids produced substantial variance in insertion gain across hearing aids. Peak insertion gain varied from 41 to 58 dB. If 10 dB reserve gain is allowed, the range of estimated peak use gain from these maximum-gain in-the-ear hearing aids is 31-48 dB.

Acoustics↗
PubMed2001

Sympathectomy improves the ear's resistance to acoustic trauma--could stress render the ear more sensitive?

Emotional stress is a phenomenon experienced by many people at some time in their lives. Some of its early manifestations, such as unbearable loudness of ambient sounds and sensations of dizziness, might be linked to inner ear dysfunction. Although the inner ear is supplied with a substantial sympathetic innervation, previous studies have failed to demonstrate any significant functional impact. We show here that in the awake guinea pig and following unilateral ablation of the superior cervical ganglion, the temporary threshold shift induced by a 1-min exposure to 8 kHz pure tone at 96 dB sound pressure level was reduced by as much as 40 dB. Of interest, the protective effect was bilateral suggesting an intimate relationship between the sympathetic and the olivocochlear efferent systems. The data presented here provide new evidence for a key role for the sympathetic system in modulating temporary threshold shifts following exposure to moderate sound stimulation. This opens new perspectives for investigation of sympathetic control in noise-induced permanent hearing losses.

Acetylcholine↗
PubMed2007

In vivo areal modulus of elasticity estimation of the human tympanic membrane system: modelling of middle ear mechanical function in normal young and aged ears.

The quasi-static elastic properties of the tympanic membrane system can be described by the areal modulus of elasticity determined by a middle ear model. The response of the tympanic membrane to quasi-static pressure changes is determined by its elastic properties. Several clinical problems are related to these, but studies are few and mostly not comparable. The elastic properties of membranes can be described by the areal modulus, and these may also be susceptible to age-related changes reflected by changes in the areal modulus. The areal modulus is determined by the relationship between membrane tension and change of the surface area relative to the undeformed surface area. A middle ear model determined the tension-strain relationship in vivo based on data from experimental pressure-volume deformations of the human tympanic membrane system. The areal modulus was determined in both a younger (n = 10) and an older (n = 10) group of normal subjects. The areal modulus for lateral and medial displacement of the tympanic membrane system was smaller in the older group (mean = 0.686 and 0.828 kN m(-1), respectively) compared to the younger group (mean = 1.066 and 1.206 kN m(-1), respectively), though not significantly (2p = 0.10 and 0.11, respectively). Based on the model the areal modulus was established describing the summated elastic properties of the tympanic membrane system. Future model improvements include exact determination of the tympanic membrane area accounting for its shape via 3D finite element analyses. In vivo estimates of Young's modulus in this study were a factor 2-3 smaller than previously found in vitro. No significant age-related differences were found in the elastic properties as expressed by the areal modulus.

Adult↗
PubMed1999

Inner ear damage in TORP-operated ears: experimental study on danger from environmental air pressure changes.

In some cases of sudden inner ear hearing loss in ears with a total ossicular replacement prosthesis, the prosthesis has been found to be penetrating the footplate. Some authors have assumed an external pressure increase for this event. In this study I tried to estimate experimentally the pressure needed for perforating a normal footplate in a temporal bone model. From the data I concluded that "cracking" the footplate can hardly be due to 1 major event of increased pressure. On the other hand, different mechanisms making the footplate a "weak spot" must be discussed and further investigated. In those cases, secondary to thinned or even perforated footplates, environmental pressure changes may be dangerous.

Air Pressure↗
PubMedDate not supplied

Tympanic membrane structure during a Staphylococcus aureus-induced middle ear infection. A study in the rat middle ear.

In response to a Staphylococcus aureus-induced middle ear infection the tympanic membrane showed infiltration of polymorphonuclear granulocytes, lymphocytes, and macrophages and increased areas covered by ciliary and secretory epithelium. These reactions, which were comparable to the cellular and mucociliary responses seen in the middle ear mucosa during infection, were restricted to the pars flaccida and to predominantly the annular and manubrial regions of the pars tensa. This showed that the greater part of the tympanic membrane, where the lamina propria is composed of collagenous bundles and only very thin layers of loose connective tissue, is hardly affected by or barely responds to the inflammatory stimulus.

Animals↗
PubMed1987

Speech understanding and directional hearing for hearing-impaired subjects with in-the-ear and behind-the-ear hearing aids.

With respect to acoustical properties, in-the-ear (ITE) aids should give better understanding and directional hearing than behind-the-ear (BTE) aids. Also hearing-impaired subjects often prefer ITEs. A study was performed to assess objectively the improvement in speech understanding and directional hearing afforded by ITE aids versus BTEs. In 28 hearing-impaired subjects, who visited our Centre for a check-up of their ITEs, the following parameters were measured: (a) thresholds for third-octave bandpass noises between 0.25 and 4 kHz, (b) speech reception thresholds for short Dutch sentences in quiet and with background noise, (c) directional hearing. All three experiments were done binaurally with the subjects wearing their ITEs, BTEs, and no hearing aid. With the 2-cc coupler, the gain used by the subject was measured. The SRT values for the ITE were significantly lower than those for BTE. More gain at 2 and 4 kHz in the ITE proved to be a responsible factor for this improvement. Directional hearing was not improved by wearing an ITE. Large interindividual differences were found between functional gain and the 2-cc coupler measurements. The mean functional gain at 4 kHz for an ITE is higher than the gain measured in a 2-cc coupler. For a BTE, the functional gain at 2 and 4 kHz is lower than the 2-cc coupler gain.

Adult↗
PubMed1993

In-the-ear and behind-the-ear hearing aids in the elderly.

A significant proportion of new hearing aid fittings are rejected by elderly patients. One of the reasons for this is their inability to correctly fit the earmould and hearing aid correctly. In this study we compared the ease of fitting of a behind-the-ear hearing aid with a specially modified skeleton earmould with an in-the-ear (ITE) hearing aid, in an elderly subject group. The modified skeleton earmould was found to be easiest to use. However, the ITE hearing aid presented handling problems only in subjects over 75 years of age. Further analysis of the results revealed that the majority of handling problems are found in female subjects in the over-75 age group.

Aged↗
PubMed1994

Some factors influencing choice of type of hearing aid in the UK: behind-the-ear or in-the-ear.

Questioning potential users of National Health Service behind-the-ear (BTE) hearing aids indicated that for some the perception of stigma associated with visible aids is a powerful deterrent to acceptance and use. To investigate further the role of stigma in hearing aid acceptance, 184 individuals who had been fitted with NHS BTE hearing aids and who had also purchased in-the-ear (ITE) hearing aids through a discounted price scheme at Withington Hospital were asked why they had made the decision to purchase, and what they perceived as the benefits of the ITE aid relative to the BTE model. The primary factor both in terms of reason for purchase and perceived benefit was the greater cosmetic acceptability of the smaller aids. Comfort in wear was the second perceived benefit. Sound quality was ranked only third. Ease of use with spectacles was the second most common reason given for purchase. These studies suggest that in a small but significant percentage of hearing aid candidates the perception of stigma is a powerful deterrent to take-up and use. This perception needs to be recognized and addressed if the most effective service is to be provided to the hearing impaired.

Auditory Threshold↗
PubMed1992

[Middle ear inflammation and fluid accumulation in the middle ear in Icelandic children].

The bacterial flora was examined in 108 Icelandic children treated for middle ear inflammations during the period, 1986-1989. Among children with acute otitis media, growth of H. influenzae was obtained in pure cultures in 54 per cent of cases. Where inflammation had caused tympanic membrane rupture, both H. influenzae and S. pneumoniae were cultured in 58 per cent of the samples. In the group with persistent seromucous secretion in the middle ear, 60.5 per cent of the samples were abacterial. S. aureus was the species most commonly isolated in samples from children with chronic discharge. The results suggest H. influenzae to be more common in acute otitis media in Iceland than elsewhere.

Child, Preschool↗