scholarly journals Frequency of the mitochondrial A1555G mutation in Iranian patients with nonsyndromic hearing impairment

2012 ◽  
Vol 5 (10) ◽  
pp. 1-6 ◽  
Author(s):  
M. Montazer Zohour
Keyword(s):  
Hearing Impairment ◽  
A1555g Mutation ◽  
Iranian Patients

scholarly journals Mitochondrial non-syndromic sensorineural hearing loss: a clinical, audiological and pathological study from Italy, and revision of the literature

2008 ◽  
Vol 28 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Stefano Berrettini ◽  
Francesca Forli ◽  
Susanna Passetti ◽  
Anna Rocchi ◽  
Luca Pollina ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Mitochondrial Dna ◽  
Sensorineural Hearing Loss ◽  
Hearing Impairment ◽  
Sensorineural Hearing ◽  
Pathological Study ◽  
Mtdna Mutations ◽  
A1555g Mutation ◽  
Sensorineural Hearing Impairment

Over the last decade, a number of distinct mutations in the mtDNA (mitochondrial DNA) have been found to be associated with both syndromic and non-syndromic forms of hearing impairment. Their real incidence as a cause of deafness is poorly understood and generally underestimated. Among the known mtDNA mutations, the A1555G mutation in the 12S gene has been identified to be one of the most common genetic cause of deafness, and it has been described to be both associated to non-syndromic progressive SNHL (sensorineural hearing loss) and to aminoglycoside-induced SNHL. In the present study, we have investigated the presence of mtDNA alterations in patients affected by idiopathic non-syndromic SNHL, both familiar and sporadic, in order to evaluate the frequency of mtDNA alterations as a cause of deafness and to describe the audiological manifestations of mitochondrial non-syndromic SNHL. In agreement with previous studies, we found the A1555G mutation to be responsible for a relevant percentage (5.4%) of cases affected with isolated idiopathic sensorineural hearing impairment.

Large-Scale Screening of Mitochondrial DNA Mutations Among Iranian Patients with Prelingual Nonsyndromic Hearing Impairment

2012 ◽  
Vol 16 (4) ◽  
pp. 271-278 ◽  
Author(s):  
Mostafa Montazer Zohour ◽  
Mohammad Amin Tabatabaiefar ◽  
Fatemeh Azadegan Dehkordi ◽  
Effat Farrokhi ◽  
Mohammad Taghi Akbari ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Hearing Impairment ◽  
Large Scale ◽  
Mitochondrial Dna Mutations ◽  
Dna Mutations ◽  
Large Scale Screening ◽  
Iranian Patients

Relevance of the A1555G Mutation in the 12S rRNA Gene for Hearing Impairment in Austria

2007 ◽  
Vol 28 (7) ◽  
pp. 884-886 ◽  
Author(s):  
Reinhard Ramsebner ◽  
Trevor Lucas ◽  
Christian Schoefer ◽  
Martin Ludwig ◽  
Wolf-Dieter Baumgartner ◽  
...  
Keyword(s):  
Hearing Impairment ◽  
12S Rrna ◽  
Rrna Gene ◽  
A1555g Mutation ◽  
12S Rrna Gene

scholarly journals Analysis of mitochondrial A1555G mutation in infants with hearing impairment

2018 ◽  
Author(s):  
Lihua Wu ◽  
Ruiyu Li ◽  
Juan Chen ◽  
Yanping Chen ◽  
Meijun Yang ◽  
...  
Keyword(s):  
Hearing Impairment ◽  
A1555g Mutation

Hearing Aid Amplification Reduces Communication Effort of People With Hearing Impairment and Their Conversation Partners

2020 ◽  
Vol 63 (4) ◽  
pp. 1299-1311 ◽  
Author(s):  
Timothy Beechey ◽  
Jörg M. Buchholz ◽  
Gitte Keidser
Keyword(s):  
Hearing Impairment ◽  
Hearing Aid ◽  
Normal Hearing ◽  
Referential Communication ◽  
Hearing Impaired ◽  
Directional Hearing ◽  
Acoustic Environment ◽  
Communication Task ◽  
Acoustic Environments ◽  
The Impact

Objectives This study investigates the hypothesis that hearing aid amplification reduces effort within conversation for both hearing aid wearers and their communication partners. Levels of effort, in the form of speech production modifications, required to maintain successful spoken communication in a range of acoustic environments are compared to earlier reported results measured in unaided conversation conditions. Design Fifteen young adult normal-hearing participants and 15 older adult hearing-impaired participants were tested in pairs. Each pair consisted of one young normal-hearing participant and one older hearing-impaired participant. Hearing-impaired participants received directional hearing aid amplification, according to their audiogram, via a master hearing aid with gain provided according to the NAL-NL2 fitting formula. Pairs of participants were required to take part in naturalistic conversations through the use of a referential communication task. Each pair took part in five conversations, each of 5-min duration. During each conversation, participants were exposed to one of five different realistic acoustic environments presented through highly open headphones. The ordering of acoustic environments across experimental blocks was pseudorandomized. Resulting recordings of conversational speech were analyzed to determine the magnitude of speech modifications, in terms of vocal level and spectrum, produced by normal-hearing talkers as a function of both acoustic environment and the degree of high-frequency average hearing impairment of their conversation partner. Results The magnitude of spectral modifications of speech produced by normal-hearing talkers during conversations with aided hearing-impaired interlocutors was smaller than the speech modifications observed during conversations between the same pairs of participants in the absence of hearing aid amplification. Conclusions The provision of hearing aid amplification reduces the effort required to maintain communication in adverse conditions. This reduction in effort provides benefit to hearing-impaired individuals and also to the conversation partners of hearing-impaired individuals. By considering the impact of amplification on both sides of dyadic conversations, this approach contributes to an increased understanding of the likely impact of hearing impairment on everyday communication.

Relationships Between Subjective Ratings and Objective Measures of Performance in Speechreading Sentences

1997 ◽  
Vol 40 (4) ◽  
pp. 900-911 ◽  
Author(s):  
Marilyn E. Demorest ◽  
Lynne E. Bernstein
Keyword(s):  
Hearing Impairment ◽  
Performance Evaluations ◽  
Objective Measures ◽  
Large Individual ◽  
Subjective Ratings ◽  
Objective Performance ◽  
Phonetic Distance ◽  
Stimulus Length ◽  
Measures Of Performance ◽  
Confidence Scale

Ninety-six participants with normal hearing and 63 with severe-to-profound hearing impairment viewed 100 CID Sentences (Davis & Silverman, 1970) and 100 B-E Sentences (Bernstein & Eberhardt, 1986b). Objective measures included words correct, phonemes correct, and visual-phonetic distance between the stimulus and response. Subjective ratings were made on a 7-point confidence scale. Magnitude of validity coefficients ranged from .34 to .76 across materials, measures, and groups. Participants with hearing impairment had higher levels of objective performance, higher subjective ratings, and higher validity coefficients, although there were large individual differences. Regression analyses revealed that subjective ratings are predictable from stimulus length, response length, and objective performance. The ability of speechreaders to make valid performance evaluations was interpreted in terms of contemporary word recognition models.

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