The effect of stimulus-frequency ratio on distortion product otoacoustic emission components

2005 ◽  
Vol 117 (6) ◽  
pp. 3766-3776 ◽  
Author(s):  
Sumitrajit Dhar ◽  
Glenis R. Long ◽  
Carrick L. Talmadge ◽  
Arnold Tubis
Keyword(s):  
Frequency Ratio ◽  
Stimulus Frequency ◽  
Otoacoustic Emission ◽  
Distortion Product Otoacoustic Emission ◽  
Distortion Product

Exploring Optimal Stimulus Frequency Ratio for Measurement of the Quadratic f 2 –f 1 Distortion Product Otoacoustic Emission in Humans

2018 ◽  
Vol 61 (7) ◽  
pp. 1794-1806
Author(s):  
Rachael R. Baiduc ◽  
Sumitrajit Dhar
Keyword(s):  
Otoacoustic Emissions ◽  
Endolymphatic Hydrops ◽  
Stimulus Frequency ◽  
Otoacoustic Emission ◽  
Normal Hearing ◽  
Distortion Product Otoacoustic Emission ◽  
Clinical Implementation ◽  
Distortion Product ◽  
Recent Interest ◽  
Stimulus Parameters

Purpose Distortion product otoacoustic emissions (DPOAEs) are a by-product of active cochlear processes that lead to the compressive nonlinearity of healthy ears. The most commonly studied emission is at the frequency 2f 1 –f 2 , but there has been recent interest in using the quadratic distortion product at the frequency f 2 –f 1 to detect cochleopathies including endolymphatic hydrops. Before the DPOAE at f 2 –f 1 can be applied clinically in any capacity, optimal stimulus parameters for its elicitation must be established. Method We investigated stimulus parameters for the DPOAEs at f 2 –f 1 and 2f 1 –f 2 in 23 adults with normal hearing. Logarithmically swept tones between approximately 0.6 and 20 kHz (L 1 = L 2 = 70 dB SPL) served as the higher frequency stimulus (f 2 ). DPOAEs were measured for 6 f 2 /f 1 ratios: 1.14, 1.18, 1.22, 1.30, 1.32, and 1.36. Results Both DPOAEs were consistently measurable. In line with previous investigations, the highest levels of the DPOAE at 2f 1 –f 2 were generated between f 2 /f 1 ratios of 1.14–1.22, with a peak in the level ratio function at 1.22. In contrast, f 2 –f 1 was less influenced by ratio, although the narrowest ratio (1.14) produced slightly higher levels across frequency. Conclusion The DPOAE at f 2 –f 1 is measurable in individuals with normal hearing up to f 2 of 20 kHz at narrow f 2 /f 1 ratios. Measurements at additional stimulus levels and in subjects with hearing impairment will be needed before clinical implementation.

Pengaruh sisplatin dosis tinggi terhadap penurunan fungsi sel rambut luar koklea

2013 ◽  
Vol 40 (2) ◽  
Author(s):  
Asti Kristianti ◽  
Teti Madiadipoera ◽  
Bogi Soeseno
Keyword(s):  
Hair Cells ◽  
Malignant Neoplasm ◽  
Otoacoustic Emission ◽  
Outer Hair Cells ◽  
High Dose ◽  
Distortion Product Otoacoustic Emission ◽  
Inclusion Criteria ◽  
Cochlear Hair Cells ◽  
Distortion Product ◽  
Bilateral Sensorineural Hearing Loss

Background: Chemotherapy is worldwide used nowadays, and its toxicity still remain a problemespecially toxicity to the ear (ototoxicity). Cisplatin (cis-diamminedichloroplatinum) is one of themost commonly used chemotherapy and highly potent in treating epithelial malignancies. Ototoxicitycaused by cisplatin is irreversible, progressive, bilateral, sensorineural hearing loss especially on highfrequency (4-8 KHz) accompanied by tinnitus. Purpose: To observe the cochlear outer hair cells damagein malignancies patients treated with cisplatin. Methods: This study is an observational analytic studywith prospective design to determine the influence of high dose cisplatin on cochlear outer hair cellsfunction. The research was carried out at the ENT-HNS Department, Hasan Sadikin General HospitalBandung, from November 2007 until June 2008. Audiometry, tympanometry, and distortion productotoacoustic emission (DPOAE) examinations were conducted before chemotherapy and DPOAE, andtimpanometry was again measured three days after first and second cycles of cisplatin administration. McNemar test was performed to calculate the effects of high-dose cisplatin to the cochlear outer haircells function. To compare pre and post-cisplatin on alteration of cochlear hair cells function, Wilcoxontest was used. Results: In this study 60 ears from 30 subjects that meet the inclusion criteria, consistedof 25 man (83.3%) and 5 women (16.7%). The prevalence of damaged cochlear outer hair cells were63% at first cycle and 70% at second cycle of cisplatin administration. The decline of cochlear outerhair cells function was significant (p<0.001). Conclusion: High-dose cisplatin decreases cochlear outerhair cells function in patients with malignant neoplasm. Abstrak : Latar belakang: Kemoterapi sekarang rutin digunakan secara klinis di seluruh dunia. Sejalan denganhal tersebut toksisitas kemoterapi, khususnya terhadap telinga saat ini menjadi perhatian. Sisplatin(cis-diamminedichloroplatinum) adalah salah satu obat kemoterapi yang paling banyak digunakandan paling manjur untuk terapi keganasan epitelial. Efek ototoksik sisplatin yaitu terjadi gangguandengar sensorineural yang irreversible, progresif, bilateral pada frekuensi tinggi (4-8 kHz), dan disertaidengan tinitus. Tujuan: Untuk menilai penurunan fungsi sel rambut luar koklea pada penderita tumorganas sesudah pemberian sisplatin dosis tinggi dengan menggunakan DPOAE. Metode: Studi analitikobservasional dengan rancangan prospektif di Bagian IK. THT-KL RS. Hasan Sadikin Bandung mulaibulan November 2007 sampai dengan Juni 2008. Pada penelitian ini dilakukan pemeriksaan audiometrinada murni, timpanometri, dan distortion product otoacoustic emission (DPOAE) prakemoterapi, kemudianDPOAE dan timpanometri diulang tiga hari sesudah siklus pertama dan kedua kemoterapi sisplatin. Datayang diperoleh diuji dengan uji McNemar dan uji Wilcoxon. Hasil: Dari penelitian didapat 60 telingadari 30 subjek penelitian yang memenuhi kriteria inklusi yang terdiri dari 25 laki-laki (83,3%) dan 5perempuan (16,7%). Insidens penurunan fungsi sel rambut luar koklea sebesar 63% (38 kasus) sesudahsiklus pertama dan 70% (42 kasus) sesudah siklus kedua. Hubungan penurunan fungsi sel rambut luarkoklea memberikan nilai yang sangat bermakna sejak pemberian siklus pertama (p<0,001). Kesimpulan:Pemberian sisplatin dosis tinggi pada penderita tumor ganas menyebabkan penurunan fungsi sel rambutluar koklea.Kata kunci: kemoterapi, sisplatin dosis tinggi, sel rambut luar koklea.

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