Development of an Arabic "Command in Noise" Hearing Test to Assess Fitness for Duty.

Objective: The goal is to implement the developed speech material in a hearing test to assess auditory fitness for duty (AFFD), specifically in areas where the intelligibility of spoken commands is essential. Design: In study 1, a speech corpus with equal intelligibility was constructed using constant stimuli to test each target word's psychometric functions. Study 2 used an adaptive interleaving procedure to maximize equalized terms. Study 3 used Monte Carlo simulations to determine speech test accuracy. Study sample: Study 1 (n = 24) and study 2 (n = 20) were completed by civilians with normal hearing. Study 3 ran 10,000 simulations per condition across various conditions varying in slopes and speech recognition thresholds (SRTs). Results: Studies 1 and 2 produced three 8-word wordlists. The mean, standard deviation in dB SNR is -13.1 1.2 for wordlist 1, -13.7 1.6 for wordlist 2, and -13.7 1.3 for wordlist 3, with word SRTs within 3.4 dB SNR. Study 3 revealed that a 6 dB SNR range is appropriate for equally understandable speech using a closed-set adaptive technique. Conclusion: The developed speech corpus may be used in an AFFD measure. Concerning the homogeneity of the speech in noise test material, care should be taken when generalizing and using ranges and standard deviations from multiple tests.

Utilization of amplicon-based targeted sequencing panel for the massively parallel sequencing of sporadic hearing impairment patients from Saudi Arabia.

BACKGROUND: Hearing Impairment (HI) can have genetic or environmental causes and in some cases, an interplay of both. Genetic causes are difficult to determine as mutations in more than 90 genes have been shown recently to be responsible for HI. Providing a genetic diagnostic test for HI is therefore a challenge especially for ethnic groups where GJB2 mutations are shown to be rare. RESULTS: Here we show the design and implementation of an amplicon-based targeted sequencing panel that allows the simultaneous sequencing of 87 HI genes. Mutations identified included known pathogenic mutations and novel variants with unknown significance. The diagnostic rate of this panel is 28 % when only pathogenic variants were reported. However, an additional 28 % harbored recurrent combinations of novel or rare single nucleotide variants in the OTOF or PCDH15 genes. Such combinations were not identified in healthy individuals. CONCLUSIONS: Targeted sequencing approach is a very useful strategy for the identification of mutations affecting the HI genes because of its relatively fast turn-around time and cost effectiveness compared to whole-exome sequencing. Further novel or rare variants could be identified by implementing a large-scale screening of HI using our panel which will eventual lead to a higher diagnostic rate.

Prevalence of hearing loss among Saudi type 2 diabetic patients.

OBJECTIVE: To compare hearing impairment and audiometric shapes associated with type 2 diabetes mellitus (T2DM) with an age-matched control group in the Saudi population. METHODS: This is an observational case-control study at a tertiary academic referral center. We recruited 196 individuals (age; 29-69 years) attending the Department of Otolaryngology, King Abdulaziz University Hospital between January 2005 to December 2009, and grouped them into T2DM (n=109) and control (n=87) groups. We excluded patients with a history of noise exposure, conductive hearing loss, ototoxic medications, and a positive family history of hearing impairment. Age, gender, family history, duration of T2DM, current treatment, and presence of diabetic complications were noted. Pure tone hearing (in decibels [dB])was recorded. Data were statistically analyzed against the matched control group. RESULTS: We identified a strong relationship between T2DM and low and mid frequencies hearing loss than the matched controls. A flat audiogram was the most common audiometric shape observed. Patients with associated diabetic complications were at a higher risk of hearing loss, while hyperglycemic control by insulin was also observed to be a risk factor for hearing loss. CONCLUSION: The T2DM is strongly associated with hearing loss especially in the low and mid frequencies. Several factors including age, diabetes control by insulin, and presence of complications, may be risk factors for hearing loss in DM patients.

Spectrum of GJB2 mutations in a cohort of nonsyndromic hearing loss cases from the Kingdom of Saudi Arabia.

Nonsyndromic hearing loss (NSHL) affects a substantial proportion of newborns in the world every year. This proportion increases proportionally with the degree of consanguineous marriages in any society. In the Kingdom of Saudi Arabia, consanguineous marriages are common practice and this is associated with a noticeably high frequency of inherited conditions affecting the resulting progeny, including NSHL. Until now there is no published data on the genetic causes of NSHL in Saudi Arabia, which greatly hindered the ability of local genetic counseling and family planning centers to distinguish between hereditary and nonhereditary forms of NSHL and subsequently could not give information on the possible inheritance of deafness. In addition, the lack of validated genetic tests for NSHL delayed the detection of deafness in affected individuals and may have lowered the efficiency of later medical interventions. Further, the population covered in this study is likely to have a multiethnic background caused by decades of religious and economic migration to this region. To address such problems, we undertook the task of unraveling the genetic causes of hearing loss in Saudi Arabia, starting with identifying the GJB2/DFNB1 mutation spectrum in a cohort of unrelated individuals suffering from mild to profound NSHL. A total of 12 reported GJB2 mutations were identified in 17 out of 109 (15.59%) NSHL cases. Biallelic GJB2 mutations were identified in 11 out of the 109 NSHL cases (10.09%), with c.35delG being the most common (7/11, 63.63%). The remaining six patients were found to have monoallelic GJB2 mutations. Interestingly, biallelic GJB2 mutations were not detected in patients of Arab tribal origins, reflecting the genetic heterogeneity of the western area of the Kingdom of Saudi Arabia. Therefore, ethnically targeted genetic screening for GJB2 mutations could be a useful tool toward the management of NSHL in this area.