Open Ear Research Articles

TORP-Vibroplasty

Surgery can often eradicate chronic middle ear disease in patients with recurrent cholesteatoma, tubal dysfunction, and others; however, in many cases, social hearing cannot be restored even after multiple revision tympanoplasties. A hearing aid is then recommended. Placement of an implantable hearing aid with its advantage of an unoccluded ear canal, irrespective of middle ear function, seems to be a promising alternative. After establishing the biomechanics of the ear in our temporal bone laboratory, various locations and attachments of a Vibrant transducer were investigated. These experiments resulted in the development of a new titanium clip holder for a Vibrant integrated total ossicular replacement prosthesis assembly with placement on the footplate. Four patients with permanent severe combined hearing loss were implanted with this device after multiple revision tympanoplasties. The first case is described in detail. Placing a transducer directly on the footplate via a rod transmission gave a better gain for the high frequencies than in the round window location. The acoustic results of the patients showed an improved gain in speech understanding, unobtainable by a conventional hearing aid. The concept of a total ossicular replacement prosthesis-vibroplasty establishes a straightforward procedure in the tympanic cavity similar to a normal tympanoplasty. The open ear canal and its superior acoustic performance offer a promising perspective for revision operations in cases of incurable middle ear dysfunction.

Hearing Protection for Student Musicians

You have accessThe ASHA LeaderFeature1 Sep 2008Hearing Protection for Student MusiciansPittsburgh School Program Works With Musicians’ Hearing Center Dee Naquin Shafer Dee Naquin Shafer Google Scholar More articles by this author https://doi.org/10.1044/leader.FTR5.13132008.5 SectionsAbout ToolsAdd to favorites ShareFacebookTwitterLinked In A school entertainment event two years ago sparked a program bringing speech-language pathologists and audiologists together in the Pittsburgh Public Schools to protect children’s hearing. It started when SLP Emily Crow attended a teachers union reception where elementary students provided the entertainment with a drumming program. “I was amazed at the abilities of these kids—they were so impressive,” Crow said, adding, “But my ears were hurting from the noise. So I asked what kind of hearing protection they wore.” After learning the children were not protecting their hearing, Crow launched a mission leading to hearing protection for children in the majority of Pittsburgh elementary schools and some middle schools. In 2007 she was honored with the Musicians’ Hearing Center (MHC) award. The MHC, part of the University of Pittsburgh Medical Center (UPMC), presented the award in conjunction with the university’s Department of Communication Sciences and Disorders and Etymotic Research, Inc. Pittsburgh children use earplugs that were designed specifically for musicians and that dampen sound across all frequencies. These plugs replicate the natural response of the open ear so that music does not lose its “brightness.” “The Pittsburgh Symphony Orchestra uses them. The kids love the fact they’re using the same equipment as professional musicians,” Crow said. “You don’t have to sell them on the idea. They think it’s cool from the get-go.” Noise Education Crow began her hearing protection quest by contacting a former professor, Catherine Palmer, UPMC’s director of audiology. Palmer was in an ideal situation to offer suggestions, having established the MHC in 2003. “Emily is just a star,” Palmer said. “It occurred to her, if you want to access elementary schools [to provide information about hearing protection] the best way is with SLPs—there is one in every school but there is not an audiologist in every school.” The MHC carries out public education by targeting colleges and high schools. The center encourages musicians to do more to prevent hearing loss. Musicians are a population who face a tremendous amount of noise exposure that leads to hearing loss that is 100% preventable, said Palmer. “We tailor the educational program to the school,” she said. Students learn how the ear works, the effects of loud sound, the volume levels of various instruments and other common sounds, and how to protect their hearing. Palmer added, “Then we teach them how to use the earplugs. In some schools we do the program for the teachers and they then educate their students.” People often fail to protect their hearing because no damage seems apparent until years later, she said. “If you damaged your ears and they bled, people would do something about it,” she added. The MHC wants people to understand that protecting hearing is no different from wearing goggles in chemistry class or helmets on the football field. Younger Students Crow knew that MHC was working with high schools and asked Palmer if she had thought about taking the hearing protection program to elementary schools. Crow discussed the idea with her supervisor, Donna Westbrooks-Martin, who then made arrangements with Palmer to speak with Pittsburgh school SLPs and some music teachers. As participants, they could support as little or as much involvement as seemed necessary, making sure children were wearing hearing protection. Since then, Crow has navigated the process of educating teachers about how to use the earplugs most effectively, Palmer said. Simple processes include labeling each case with the child’s name, keeping the earplugs in the band room so they aren’t left at home, and requiring their use in order to participate. “Touching base with Dr. Palmer was the right thing to do,” Crow said. “She spoke to our entire staff and there was a big increase in involvement.” The Musicians’ Hearing Center of the University of Pittsburgh Medical Center annually honors an individual who improves the health and quality of life of others in Southwestern Pennsylvania by promoting hearing protection. Awardees receive $1,000 to further their work of hearing protection. Emily Crow can be contacted at [email protected]. Catherine Palmer can be contacted at mailto:[email protected] Author Notes Dee Naquin Shafer, an assistant managing editor of The ASHA Leader, can be contacted at [email protected]. Advertising Disclaimer | Advertise With Us Advertising Disclaimer | Advertise With Us Additional Resources FiguresSourcesRelatedDetails Volume 13Issue 13September 2008 Get Permissions Add to your Mendeley library History Published in print: Sep 1, 2008 Metrics Downloaded 238 times Topicsasha-topicsleader_do_tagasha-article-typesCopyright & Permissions© 2008 American Speech-Language-Hearing AssociationLoading ...

Phase I and Animal Studies of the TACA Implanted Hearing Aid

Problem Hearing aid technologies are lacking in terms of cosmesis and comfort, encumber activities such as showering and swimming, and can distort the user's voice due to occlusion effect. The Transcutaneous Air Conduction Aid (TACA) has been developed as an alternative for patients with mild-to-moderate high-frequency sensorineural hearing loss. This new device is designed to bring amplified sound into an open ear canal in an invisible manner. This study presents our investigation into the additional challenge of a percutaneous device at risk for marsupialization and infection at the device-skin interface. Methods TACA phantoms, coated with a fibrous titanium mesh biomaterial, were tested in long-term preclinical implantation studies. Histomorphometric comparison of mesh coated and uncoated TACA phantoms was performed in 3 rabbits at 90 and 180 days. A follow-up study in 7 rabbits was performed to temporally characterize wound healing around the mesh coated implants from 1–13 weeks. Based on promising animal results, a phase I FDA human trial was conducted lasting 6 months. Results Preliminary histomorphometric studies (N=18 phantoms with mesh, 6 without mesh) in 3 rabbits demonstrated that the titanium mesh biomaterial prevented marsupialization and infection at 90 and 180 days. The follow-up study of 42 mesh-coated phantoms in 7 rabbits demonstrated that the epidermal seal was reestablished around the percutaneous projection at 3 weeks, with supporting vascularized connective tissue ingrowth complete at 6 weeks. The human phase I data demonstrated connective tissue ingrowth and epidermal sealing with no evidence of marsupialization or infection. Conclusion The TACA may offer an alternative for patients with sensorineural mild-to-moderate sloping high frequency hearing loss. Percutaneous implant studies in rabbits and man demonstrated the safety of this novel percutaneous device. Significance Preclinical and clinical demonstration of feasibility and safety. Support This work was supported by Implanted Acoustics, Santa Clarita, California.

A Multicenter Trial of an Assess-and-Fit Hearing Aid Service Using Open Canal Fittings and Comply Ear Tips

Large potential benefits have been suggested for an assess-and-fit approach to hearing health care, particularly using open canal fittings. However, the clinical effectiveness has not previously been evaluated, nor has the efficiency of this approach in a National Health Service setting. These two outcomes were measured in a variety of clinical settings in the United Kingdom. Twelve services in England and Wales participated, and 540 people with hearing problems, not previously referred for assessment, were included. Of these, 68% (n = 369) were suitable and had hearing aids fitted to NAL NL1 during the assess-and-fit visit using either open ear tips, or Comply ear tips. The Glasgow Hearing Aid Benefit Profile was used to compare patients fitted with open ear tips with a group of patients from the English Modernization of Hearing Aid Services evaluation, who used custom earmolds. This showed a significant improvement in outcome for those with open ear tips after allowing for age and hearing loss in the analysis. In particular, the benefits of using bilateral open ear tips were significantly larger than bilateral custom earmolds. This assess-and-fit model showed a mean service efficiency gain of about 5% to 10%. The actual gain will depend on current practice, in particular on the separate appointments used, the numbers of patients failing to attend appointments, and the numbers not accepting a hearing aid solution for their problem. There are potentially further efficiency and quality gains to be made if patients are appropriately triaged before referral.

Capturing blocked‐entrance binaural signals from open‐entrance recordings

Binaural recordings enable us to capture all sound attributes including spatial information, room effect, and source characteristics in a given environment. It has been shown that blocked‐entrance binaural recordings provide advantages over open‐entrance recordings, primarily because the blocked‐entrance recordings is not influenced by the ear canal acoustics of the individual for which it is recorded. However, blocking the ear canal for recoding imposes an obvious disruption to normal hearing conditions, which may be unacceptable for applications in which binaural audio capturing is desired but without interfering the individual's hearing and doing. In this work we propose a strategy for the recording of binaural audio with minimal hearing interference, and for transforming these recordings to blocked‐entrance versions that are more suitable for analysis and reproduction of binaural audio in a more general context. To this purpose, equalization filters are derived from the ratio between blocked and open ear canal transfer functions. Different transfer‐function measuring techniques and inverse filtering methods are evaluated.

Efalizumab in routine use: a clinical experience

With the advent of biological therapies, continuous long-term control of psoriasis is now becoming a reality. We report our experience with biologics based on the treatment of more than 550 psoriatic patients with such compounds at our special outpatient care center of Bio-Immunotherapy at the Department of Dermatology of the Medical University of Vienna. Approximately 220 of these patients are currently receiving efalizumab. In our hands, efalizumab was generally found to be safe and well tolerated and, after 12 weeks of treatment, resulted in a PASI reduction of 50% or more in approximately two-thirds of patients treated. In most of these 'early' responders, the therapeutic efficacy of efalizumab can be maintained for a prolonged period of time, in certain patients up to 36 months. Flares occurring during long-term therapy were rare and, in most instances, triggered by infections. During such flares, we usually do not discontinue efalizumab therapy, but rather try to combat the infection by appropriate antibiotics and to control the activity of the cutaneous eruption by the addition of topical (corticosteroids) and, when needed, systemic (e.g. methotrexate 15-20 mg week(-1) for 8-10 weeks) medication. In such a situation, it is of utmost importance for the care-taking physician to closely communicate with the affected patients in a scientifically competent fashion and to have an open ear for their concerns. This helps and improves patient compliance and minimizes the need for treatment discontinuation.

Audience is a verb: A conversation with Darren Copeland

Darren Copeland: I think in a lot of cases I’m taking my studio background and trying to apply it to public situations. Playing on the 401 is perhaps an extension of other installations that I’ve done, which have been in public spaces, where I may have been creating something in relation to the visual world, having sound that complements it or comments on it in some fashion. Last November at the Inter active ’05 festival in Toronto I made a piece that was called Intersections. It was on a pedestrian bridge, about 100 feet long, that goes over the train tracks. The bridge connects the two buildings of the Metro Convention Centre. In one of the buildings of the centre, the Toronto Art Fair was going on , and Intersections was a kind of welcoming piece in a sense. I did recordings of the br idge and people going by and stuff-just the sound of people walking through it, and also the sound of the trains underneath as they passed by. I was interested in playing those sounds back into the space and then manipulating them, to kind of alter reality and create a kind of ambiguity between what is real and what is imaginary. And so, sometimes , the sound is quite manipulated and has maybe only a very slight sense of it being a train or someone talking or some one walking, but other times the sound is realistic .There’s that sort of “look over the shoulder” thing that sometimes people have when they think they hear something that’s not actually there. It also kind of altered people’s awareness of space. The bridge was no longer just a way to get from one place to another; it was a place to visit. I think it worked in that way. I’d like to do mor e pieces like that. For the Open Ears festivals in Kitchen er I have been doing pieces in the City Hall rotunda. Those are eight-channel soundscape pieces.

Open-canal fittings

Fitting hearing aids involves innovation and compromise. This is especially true in deciding the tightness of the fit, whether of an earmold or a custom product. Tight-fitting instruments are good for obtaining high levels of gain and output, especially in the lower frequencies, and for minimizing feedback problems. However, they often are uncomfortable, sometimes create an unacceptable occlusion effect, and can give the patient a “plugged up” sensation. If the patient has normal or near-normal hearing in the lower frequencies, it is common practice to move toward a more open fitting to alleviate occlusion and let low frequencies into the ear naturally. In this case, the compromise is reduced gain and output, and a greater chance of unwanted acoustic feedback. There is little documentation of the first open-canal (OC) fittings, but we know they received considerable attention immediately after the CROS-type hearing aid was introduced.1 It was quickly discovered that the open earpieces (or tubing only) used for the CROS hearing aid also could be used for ipsilateral high-frequency amplification (hence, the term IROS [ipsilateral routing of signals], referring to a large vent). In the late 1960s, researchers showed that OC fittings could provide useful high-frequency amplification.2-4 In the ensuing decades, there wasn’t much excitement about open fittings, though there was some renewed interest during the Libby horn’s peak of popularity5 and on other occasions when a product designed specifically for high-frequency hearing loss was introduced.6 The ho-hum attitude toward OC fittings that persisted for more than 30 years was stirred up considerably a few years ago when five key aspects were combined in a single OC product: a small “cute” BTE casing, multichannel compression and gain adjustments, a thin tube channeling the sound from the hearing aid to the ear, a comfortable nonoccluding eartip, and, most importantly, effective feedbackreduction algorithms. As reviewed by Mueller,7 these five factors combine to offer a wide range of potential patient benefits, and OC products have rapidly taken over a sizable share of the total hearing aid market. While the peer-reviewed journals have published little about these modern OC fittings, several articles about this style have appeared in the trade journals, and the OC product is a hot topic at hearing aid workshops and seminars. However, there are still some key issues related to these products that need further clarification, and maybe even a couple areas where misconceptions exist. In this paper, we’ll provide some tips on OC fittings, which we hope will clarify more than they confuse.

Drilling a vent often fails to give relief from occlusion

Drilling a vent often fails to give relief from occlusion

P2104 騒音下で片耳に装着したヘッドホンから聴取する語音の明瞭度と開放耳に耳栓を挿入することの効果(一般演題:ポスター,地方の時代の産業保健,第79回日本産業衛生学会)

P2104 騒音下で片耳に装着したヘッドホンから聴取する語音の明瞭度と開放耳に耳栓を挿入することの効果(一般演題:ポスター,地方の時代の産業保健,第79回日本産業衛生学会)

The "Hearing Aid Effect" 2005

The visibility of open ear (OE) styles of hearing instruments was rigorously investigated for their potential to reduce the stigma of wearing hearing aids. Three groups of 50 young adults (150 total) rated the visibility of 6 hearing aid styles-OE, invisible completely-in-the-canal (CIC), mini in-the-canal (m-ITC), half- and full-shell in-the-ear (ITE), and behind-the-ear (BTE)-worn by a peer model with revealing hairstyle, photographed from 2 ft and at 3 different angles (45 degrees, 90 degrees, and 135 degrees). CIC was rated significantly most "invisible" at 45 degrees and 90 degrees, OE and m-ITC were next at those angles, and OE and BTE were least invisible at 135 degrees. The findings have implications for counseling potential users who are reluctant to try hearing aids for cosmetic reasons.

Open Ears, Appetite, and Adultery in A Woman Killed with Kindness

AS THOMAS EDGAR NOTES IN Lawes Resolutions of Womens Rights, some women in the early modern period were able to shift well enough (6); nevertheless, in law they were generally subject to their husbands and fathers and encouraged--at least by conduct book writers and preachers--to listen to these men figures of male authority. (1) At the same time, women were warned to guard their ears and stop them from hearing dishonestie (Overbury C4), was feared, thanks to the traditional commentary on Eve's role in the Fall, that women were more likely to be corrupted--and therefore to corrupt men--if they heard subversive or inappropriate ideas. These fears were most often expressed not concerns over male speech but unease about the female desire to listen, what Othello calls, in reference to Desdemona, her greedy (Othello 1.3.148), and appear connected to views of female sexuality. A number of critics, including Peter Stallybrass, Lynda Boose, and Douglas Bruster, discuss the link between the mouth and the vagina and the association between speech and sexual licentiousness in the period, and Linda Woodbridge notes the long-time connection between the ear and the vagina (Woodbridge 55). However, the link between all three orifices, the ear, mouth, and vagina, is often overlooked because of the current tendency to view ears passive, ever-open orifices (Kilgour 131). In contrast, in the early modern period, ears, like mouths and vaginas, were regarded not only passive openings through which the body could be penetrated, but also sites through which desire could be expressed. I therefore wish to explore how these three orifices were constructed sites of female desire and how this construction is revealed through the character of Anne Frankford in Thomas Heywood's A Woman Killed with Kindness. Not only are the ear and mouth connected one hears the speech the other produces, but they are also linked through the analogy of speech to food, an association common in the early modern period. (2) idea of speech nourishment of the soule (Primaudaye 126) was most for Protestant preachers who clearly had a vested interest in encouraging people to take in and digest the spoken word, at least when they were preaching. (3) According to these preachers, an open ear is necessary for both faith and obedience and those who exhibit a closed ear, who refuse to listen to God's word (or to God's earthly representatives), are ungodly. Protestant and Catholic writers alike revered the Virgin Mary the ideal listener because she attended to and believed what she heard, bearing God's son (the Word made flesh) a result (Hassel 54-55, 69-72). They insisted that this type of hearing was necessary for faithful, fruitful obedience. In contrast, Eve was deemed the epitome of an unfruitful hearer not only because she failed to maintain belief in God's word, accepting what the serpent said over God's earlier directive, but also because her act of listening brought the antithesis of fruitfulness--death--into the world. While Protestant ministers encouraged their congregations (and readers) to hunger for God's word and to incorporate into their bodies so that they, like the Virgin Mary, might be transformed, preachers were also aware of how other voices could interfere with digestion. As Eve discovered, what the devil and the world say is often more appealing than what God says. Robert Wilkinson writes, The diuel calleth by temptation and yee yeelde vnto it, the worlde calleth and ye listen to it, the fleshe calleth and ye come to it, but the worship of God calleth and ye care not for it (B[V.sup.v]). Such an ear, according to Richard Crooke, is an Eare (Egerton A[4.sup.r-v]). (4) Moreover, he specifically associates these adulterous ears with transgressive female sexual desire, for they are known as the Harlot is knowne, they are euer gadding to seeke their new Louers (A[5. …

Stick It in Your Ear: A Systematic Approach to Earmold Selection

Stick It in Your Ear: A Systematic Approach to Earmold Selection

Power plays

Power plays

Influence of ear canal occlusion and static pressure difference on bone conduction thresholds: Implications for mechanisms of bone conduction

The effect of air pressure change on bone conduction (BC) hearing thresholds in the occluded ear was investigated. The pump manometer system of an impedance bridge was used to change the air pressure in the ear canal of twenty-two normally hearing subjects. BC thresholds were measured with: (1) open ear; (2) the ear canal occluded with a probe tube and application of 0 daPa air pressure; and (3) the ear canal occluded with a probe tube and application of −350 daPa air pressure. Thresholds were lower in condition 2 than in condition 1, the difference decreasing from 27 dB at 2500 Hz to 4.5 dB at 2000 Hz. Thresholds were higher in condition 3 than in condition 2. The results are interpreted in terms of changes in the relative contribution of the three routes of transmission for BC sound produced by occlusion and by a static pressure difference.

Wanted: help through the jungle of hospital care

“Experiencing the world of the inpatient was for us, the inpatient family, like landing on Mars”, so writes a mother on p 2022 describing her and her husband's perception of the 2-year journey of her young, chronically ill daughter through the modern medical system—a journey that ended tragically in death. When a child is born prematurely or with a serious medical condition, or falls ill with a serious disease, parents are rapidly thrown into a turmoil of shock, anxiety, and eagerness to do the best they can for their child. Hospitals become places of hope. Doctors and nurses become helpers and companions in the fight against disease and death. Too often, however, we fail in these compassionate roles. In reality, hospitals can be bewildering and frightening places to children and also to their parents and healthy siblings. Medical care can be messy, is often painful, and the outcome may be uncertain. Parents may suddenly have to hand over the responsibility of care for their children to staff they hardly know. They become helpless bystanders. Witnessing the distress of one's sick child is one of the hardest situations for parents to be in. Distress is often caused by pain, and pain recognition can be difficult in young children. In routine practice, pain relief is still not always managed in the best possible way. Repeated necessary procedures, such as venepuncture, frequently—despite the use of local anaesthetic—lead to anticipatory fear. Doctors and nurses will strive to do their best to minimise distress but are often ill-equipped or too busy to provide the level of explanation and emotional support needed by the child and the whole family. Success of new medical interventions is measured by the numbers of patients who survive or the numbers of days those patients stay in hospital. Only rarely are quality of life or the emotional wellbeing of children, let alone their immediate family, in hospital or after discharge, taken into account. “22 children with end-stage cardiomyopathy … were supported by a mechanical assist device as a bridge to first heart transplantation, with a 77% survival rate to hospital discharge”, so the main result of a retrospective study reported in this week's issue is described (p 1967). Such an endpoint is vital if we are to understand the value of this device. But the stark reality of the necessary everyday medical care for these children and their families' anxiety, hope, and grief is hidden by these numbers. This is one of the most serious and perplexing failures of modern medicine. In a few hospitals the specialty of transplantation, like oncology, has been at the forefront of giving special support to patients and their families beyond immediate medical care. Transplant coordinators or oncology liaison officers, especially in tertiary paediatric settings, act as a link between the medical team involved in acute care and the family, and often guide a family's path through the medical system and beyond throughout the patient's life. Many have had a past background as a senior nurse and have now become a patient's and a family's advocate, adviser, helper, and friend giving practical and emotional support in and out of hospital. In its 10-year plan for the National Health Service, published in 2000, the UK Government recognised the need to make its health-care system more patient-centred and family-friendly. It drew up a plan for a Patient Advocacy and Liaison Service (PALS) in every Trust, a move strongly supported by Ian Kennedy, who chaired the inquiry into child deaths at the Bristol Royal Infirmary. The first so-called pathfinder PALS were set up in 2001. Over 500 Trusts now have these services; on average they employ 2·5 full-time staff who provide support, education, and an open ear for any concerns and problems. But this scheme is only the first step to the wider use of patient liaison personnel within a multidisciplinary team. 2·3 people for a whole Trust are simply inadequate. Every single ward that has responsibility for seriously ill patients—children and adults—should have at least two patient or family liaison officers to assist families. With this kind of support, perhaps stories like Michaela's and her parents' will belong to the dark ages of medicine—a time in which, shamefully, it still seems we are living.

Speech production in noise with and without hearing protection.

People working in noisy environments often complain of difficulty communicating when they wear hearing protection. It was hypothesized that part of the workers' communication difficulties stem from changes in speech production that occur when hearing protectors are worn. To address this possibility, overall and one-third-octave-band SPL measurements were obtained for 16 men and 16 women as they produced connected speech while wearing foam, flange, or no earplugs (open ears) in quiet and in pink noise at 60, 70, 80, 90, and 100 dB SPL. The attenuation and the occlusion effect produced by the earplugs were measured. The Speech Intelligibility Index (SII) was also calculated for each condition. The talkers produced lower overall speech levels, speech-to-noise ratios, and SII values, and less high-frequency speech energy, when they wore earplugs compared with the open-ear condition. Small differences in the speech measures between the talkers wearing foam and flange earplugs were observed. Overall, the results of the study indicate that talkers wearing earplugs (and consequently their listeners) are at a disadvantage when communicating in noise.

Communication in Noise with Acoustic and Electronic Hearing Protection Devices

The purpose of the present study was to evaluate communication ability in noise at two signal presentation levels when using acoustic and electronic hearing protection devices (HPDs). Fourteen normal hearing subjects were fitted binaurally with custom acoustic HPDs (ER-15) and custom electronic HPDs (Starkey SA T9). Probe microphone measurements were obtained on 28 ears for three experimental conditions (open ear, acoustic HPD, electronic HPD) at four input signal levels (60, 70, 80, 90 dB SPL). Also, communication in noise was evaluated for three conditions (open ear, acoustic HPD, electronic HPD) at two input signal levels (75 and 90 dB SPL) using the Hearing In Noise Test. Results indicated significantly greater attenuation as well as significantly better communication in noise for the acoustic HPD. Results also indicated that the electronic HPD failed to attenuate any input signal utilized. Although results of behavioral testing indicated that communication ability in noise was not significantly impacted by varying the signal presentation level when utilizing either HPD, a more salient finding may be that utilization of the electronic HPD may place listeners at risk for temporary or permanent sensorineural hearing loss.

Irritant potential of some constituents from the seeds of Caesalpinia bonducella (L.) Fleming

The irritant potential of four triterpenoids, isolated for the first time from the seeds of Caesalpinia bonducella, identified as f -amyrin [12-ursen-3 g -ol], g -amyrin [12-oleanex-3 g -ol], lupeol [lup-20(29)-en-3 g -ol] and lupeol acetate [lup-20(29)-en-3 g -yl acetate] was investigated by open mouse ear assay, evaluating their ID50 (irritant dose in 50% animals) after acute effects and by irritant units (IU) after chronic effects. f -Amyrin, lupeol acetate and g -amyrin were the most potent and persistent irritant compounds with red weals of 1.5-2.1 cm diameter areas of the animal skin and with lowest ID50 =0.078, 0.186 and 0.190 mg/10 w l after 1.5, 2.10 and 3.5 h, respectively. Their reactions lasted for 24 h with IU=2.5; 0.312 and 1.25 mg/10 w l, respectively. Lupeol was the least irritant and least persistent compound with ID50 =0.603 mg/10 w l after 4.5 h. Its reaction subsided before 24 h.

Performance and reaction times in monaural localization of first names in the horizontal plane

Many studies have been conducted to measure monaural azimuthal sound localization performance with different sounds varying in frequency and complexity, but few have used linguistic stimuli. The present experimental design used subjects' first names in a monaural azimuthal localization task. Analysis of response accuracy showed that subjects are not more accurate in localizing their own first name than in localizing other first names and that there was no significant advantage of one ear over another. Reaction times were shorter when the subjects localized their own first name than when they localized any other first names and there was no significant ear advantage, but localizing other first names took more time with the right than with the left ear. All stimuli were better and more quickly localized on the side of the open ear, and there was no difference in acuity or velocity of localization with the two different speaker voices used. These results suggest that first names are processed through the controlateral auditory pathway and can be analyzed in the right hemisphere.