Air Conduction Pure-tone Averages Research Articles

Neurophysiological changes in sudden deafness and in progressive sensorineural hearing loss patients studied by electrocochleography

Sudden deafness (SD) and progressive sensorineural hearing loss (PSNHL) are two different disease entities. SD is an obscure entity with diverse causes, complex pathophysiology and course. Progressive SNHL has often clear aetiology but both diseases require investigation. The aim of this study was to investigate the cochlear neurophysiological changes occurring in SD and in PSNHL by the use of electrocochleography (ECoG). 11 patients with SD related to cochlear failure (mean age 58.6 years) presented with either unilateral (n = 10) or bilateral (n = 1) SD and 31 patients (mean age 54.6 years) with progressive SNHL were studied. Transtympanic ECoG and conventional audiometry were performed. Action potential (AP), summating potential to action potential (SP/AP) ratio, and cochlear microphonic (CM) output were evaluated and compared with pure tone average air conduction thresholds (PTA). Four SD patients (36.3%) with severe hearing loss had SP/AP > 30% indicating the presence of endolymphatic hydrops (EH), w...

A longitudinal study of the association between tooth loss and age‐related hearing loss

The purpose of this study was to investigate cross-sectional and longitudinal associations between hearing acuity and tooth loss in 1156 US veterans taking part in the Veterans Affairs' Normative Aging (NAS) and Dental Longitudinal (DLS) Studies in the Boston, MA, area. The mean age was 48 years (SD = 8.9), 5.3% were edentulous, and 15.4% had < 17 teeth at baseline. Hearing acuity was determined by puretone, air- and bone-conduction audiometry, and speech discrimination tests at triennial examinations over a 20-year follow-up period. Hearing decline was defined as a change from baseline in the average puretone air-conduction thresholds of > or = 20 dB at 0.25, 0.5, 1, 2, 3, 4, 6, and 8 kHz. The explanatory variables of interest were change since baseline in dentate status (cut points at < 1, < 17, and < 20 teeth), and in the number of teeth lost (linear). Linear and logistic regression models--which controlled for baseline audiological status, age, air-bone gap, and otoscopic examination at current visit--showed that subjects who went from having > or = 17 to < 17 teeth had 1.64 times (95% CI, 1.24-2.17) as high odds of having hearing decline as those with no change in their dentate status. For every tooth lost since baseline, there was a 1.04 times as high odds (95% CI, 1.02-1.06) for hearing decline, when additional baseline and time-varying covariates were taken into account in the model.

長期留置型パパレラＩＩ型チューブの使用経験

The use of long-term middle ear ventilation tubes (Paparella type II) was retrospectively analyzed in 66 ears with otitis media with effusion, in children treated at Kagawa Medical University Hospital between January 1990 and March 1998. The average intubation period was 23.9 months. The average pure tone air conduction threshold showed a remarkable improvement of between 32.7dBHL and 16.9dBHL. Otorrhea was observed in 25 ears (37.8%), obstruction in 2 ears (3.0%), granulation in 3 ears (4.5%) and permanent ear drum perforation in 11 ears (19.6%). No cholesteatma or adhesion of the ear drum was seen. Recurrence of otitis media with effusion was found in 9 of 45 ears (20.0%). In conclusion, Paparella type II tube can be placed for a long-term period and have a low rate of reccurence, but have a high rate of otorrhea and permanent ear drum perforation.

Comparison of argon and CO2 laser stapedotomy in primary otosclerosis surgery

Purpose: The primary use for the laser in otosclerosis surgery is to create a stapes footplate fenestration that obviates the need for mechanical footplate removal. Experimental studies that evaluate the potential safety of visible (argon and potassium-titanyl-phosphate [KTP]) and invisible (CO2) light laser systems in stapes surgery report conflicting results. The purpose of this study is to compare the clinical safety and efficacy of the CO2 and argon laser systems when used for primary laser stapedotomy. Materials and Methods: A retrospective case review of 124 primary laser stapedotomies using either the argon (n = 59) or CO2 (n = 65) laser was performed. Data consisted of pre- and postoperative air and bone conduction audiometry, speech discrimination scores (SDS), intraoperative findings, and postoperative complications. Between group differences (argon v CO2) were sought using standard statistical methodology. Results: The argon and CO2 laser groups were comparable with regards to age, sex, preoperative air-bone gap, and laterality. Mean preoperative air and bone conduction pure-tone average (PTA) and SDS were somewhat higher in the CO2 laser group (P <.05). Postoperatively, both groups showed similar results in mean change in air conduction PTA, air-bone gap, and SDS, as well as in the frequency of complications. There were no anacoustic ears in either group. Conclusions: The results suggest that the argon and CO2 laser systems are comparable with regards to safety and efficacy when used by experienced surgeons for stapedotomy. (Am J Otolaryngol 2000;21:227-230. Copyright © 2000 by W.B. Saunders Company

Mastoid Surgery in the Only Hearing Ear

Every otologic procedure carries the risk of damage to the inner ear. On the other hand, cholesteatoma and uncontrolled tubotympanic disease can lead to partial or total sensorineural loss, as well as intracranial complications. Our experience of the surgical management of eight patients with an only hearing ear is presented. There were no dead ears in this series and no significant worsening of inner ear function. The air conduction pure-tone average was worse in two patients without change in bone conduction. Of the eight patients, six wear a hearing aid with success and two patients manage without an aid. The present small series confirms that patients at risk of anacusis from cholesteatoma or chronic suppurative otitis media can be offered, in experienced tertiary referral units, a safe method of stabilizing the ear and preserving useful hearing.

Hearing and acute otitis media in 13-year-old children.

Air and bone conduction thresholds of 330 unselected urban 13-year-old children with a known history of otitis were measured under ideal conditions, using standard clinical audiometry. In the subgroups of children with different numbers (0, 1-2, 3-7, > or = 8) of attacks of acute otitis media (AOM) in their history, the mean air conduction thresholds varied from 0.2 to 11.5 dB at different frequencies in different AOM subgroups. Air conduction pure tone averages (PTA, mean threshold at 0.5, 1 and 2 kHz) > 20 dB were not found in any of the ears. The mean bone conduction thresholds varied from -0.0 to 1.8 dB, depending on the subgroup and frequency (0.25 to 4.0 kHz) studied. Bone conduction PTAs > 10 dB were measured in 5 (0.8%) ears. Single bone conduction thresholds > 10 dB were found at different frequencies in 3 to 15 (0.5 to 2.3%) of the ears, and thresholds > 20 dB in only 2 ears (0.3%). The mean thresholds and number of ears with decreased hearing were distributed equally between different AOM subgroups, except that some air conduction high frequency losses were more frequent in children with > or = 8 attacks of AOM. We conclude that childhood AOM, even if it occurs frequently, seems not to have a significant harmful long-term effect on hearing.

長期留置型鼓室チューブの使用経験 小児しん出性中耳炎について

The results of long-term middle ear ventilation with a Koken tube (wide flange, A type) were retrospectively analyzed chiefly with respect to complications in 43 ears with otitis media with effusion in children aged 3 to 9 years. The average intubation period was 11 months.The average pure tone air conduction threshold showed remarkable improvement from 34.5 dBHL to 15.9 dBHL. Otorrhea, extrusion and obstruction of the tube were observed in 8 ears (18.6%), 9 ears (20.9%) and 3 ears (7.0%), respectively. No cholesteatoma or granuloma were seen. The ear drum perforation failed to close in 4 of 36 ears (11.1%) followed for more than 6 months after extrusion or removal of the tubes. Scarring of the ear drum was observed in 4 ears (12.5%). Recurrence of otitis media with effusion was seen in 15 of 32 ears (46.9%), in which the ear drum perforation was closed after extrusion or removal of the tubes.The present results indicate that the Koken tube (A type) is one of the best tubes for long-term middle ear ventilation.

Hearing and hearing loss in 5-year-old children. Pure-tone thresholds and the effect of acute otitis media.

Air and bone conduction pure-tone thresholds of 420 unselected urban children were measured with standard clinical audiometry. The mean of air conduction pure-tone averages (average threshold at 0.5, 1 and 2 kHz) was 8.6 dB HL in girls and 8.3 dB HL in boys. In only 5 ears (0.6%), was this average greater than or equal to 35 dB HL. The threshold greater than or equal to 35 dB HL at 4 kHz was found in 1.4% of the ears and at 8 kHz in 4.1%. The bone conduction threshold greater than 20 dB HL at any of the frequencies from 0.5 to 4 kHz was very rare, and only once, at 4 kHz, was it greater than 35 dB HL. Earlier attacks of acute otitis media seemed to have only a marginal long-term effect on air conduction hearing, and an almost negligible effect on bone conduction hearing.

Hearing results with the use of different tympanostomy tubes: a prospective study

The audiograms of 59 patients who had 15 different types of tubes implanted in a prospective study from 1982 to 1985 were reviewed. The audiograms were analyzed for changes in air and bone thresholds at 250, 500, 1000, 2000, 4000 and 8000 Hz. The first post-operative audiogram was tabulated for all the initial post-operative visits and for only the initial post-operative visits in which the tubes were functioning. The change in pure tone average air conduction showed a range in improvement from 22.1 dB for the Armstrong Grommet Tube to 1.9 dB for the Canoe Tube. A total of 8 tube types showed mean improvements of 10 dB or better. With the exception of the Reuter Bobbin, all mean air conduction thresholds in functioning tubes were below 20 dB. For 5 tubes the mean threshold was less than 10 dB. The Armstrong Beveled Grommet, Donaldson, and Richard's Wing tubes showed the largest improvements in air conduction threshold with mean decreases of 22.1, 18.7 and 18.3 dB, respectively. Pure tone average bone conduction for all functioning tubes improved 2.8 dB.