Otology
Adnan Darr, Karan Jolly, Jameel Muzaffar in ENT Vivas, 2023
Investigations: Audiometry: Rollover phenomenon: Reduction in word recognition score (speech recognition score) with increasing intensityPhonemic regression: Disproportionate speech recognition when compared to pure tone thresholdsTone decay/fatigue: Decreased auditory perception with sustained signal stimulus – retro-cochlear pathologyABR: Interaural latency on wave V (sensitive only to tumours >1.5 cm), or increased I–V latencyImaging: CT may show widening of IAC, and bone resorption (unlike hyperostosis in meningioma)MRI: Iso/hypo-intense on T1, T2. Hyperintense on Ga contrast, arising from IAC, with cystic component
Central Auditory Processing Disorders
James Law, Alison Parkinson, Rashmin Tamhne, David Hall in Communication Difficulties in Childhood, 2017
The first objective in the assessment of possible CAPD is to rule out a hearing loss caused by peripheral auditory dysfunction (see alsoChapters 4 and 17). The peripheral auditory system is defined as the outer ear, the tympanic membrane and the middle ear, the inner ear (cochlea) and the eighth cranial (auditory) nerve. Audiology terms and procedures important in a discussion of CAPD assessment are defined in the Glossary. Pure tone audiometry is a measure of hearing sensitivity for pure tone stimuli (sinusoids) ranging in octave frequencies from 250 Hz up to 8000 Hz and, in CAPD assessment, also including 3000 Hz and 6000 Hz. Hearing test results, recorded as the threshold in decibels hearing level (dB HL) for these frequencies, are graphed on an audiogram. A young, perfectly normal person has hearing threshold levels of 0 dB HL across this frequency region. The clinically normal region on the audiogram, however, is from 0 to 20 dB HL.
The Role of the Audiologist in Life Care Planning
Roger O. Weed, Debra E. Berens in Life Care Planning and Case Management Handbook, 2018
Pure tone audiometry is performed to determine if hearing is normal or impaired. An audiologist, using a calibrated electronic device, called an audiometer, and standardized procedures, measures hearing sensitivity. The individual being tested initially wears earphones and the audiologist presents tones of varying frequencies and intensities to each ear. When the individual hears the tone, they respond by raising their hand or pressing a response button. The lowest intensity level at which the tone is heard two out of three times is called threshold. This process is then repeated with the individual wearing a bone vibrator placed on the mastoid bone. When thresholds using earphones are outside the normal range, a comparison with the bone vibrator thresholds will indicate which part of the auditory system is responsible for the hearing loss.
Equivalent threshold sound pressure levels (ETSPLs) for RadioEar DD65v2 circumaural audiometric headphones
Published in International Journal of Audiology, 2020
In daily clinical practice, pure-tone audiometry is the primary method of assessing hearing loss. The reference zero for calibrating pure-tone audiometers is given in terms of reference equivalent threshold sound pressure levels (RETSPLs) for combinations of different types of audiometric transducers and appropriate ear simulators or couplers used for calibration. Hence, the accuracy of an audiogram strongly relies on the accuracy of the RETSPLs, which are typically provided in the international standard series ISO 389 [ISO 389-1 (2017) and ISO 389-8 (2004) for earphones]. Generally, RETSPLs are based on equivalent threshold sound pressure levels (ETSPLs), ideally determined by at least two independent studies. The preferred conditions for ETSPL determination are described in ISO 389-9 (2009), which refers to ISO 8253-1 (2010) for the hearing threshold measurement procedure.
Considering hearing loss as a modifiable risk factor for dementia
Published in Expert Review of Neurotherapeutics, 2022
Katharine K. Brewster, Jennifer A. Deal, Frank R. Lin, Bret R. Rutherford
The ability to hear depends on the precise encoding of sound into a neural signal by the peripheral auditory system followed by decoding of the signal into meaning by the brain. When used in the context of this review and unless stated otherwise, ‘hearing loss’ refers to impairments of the peripheral auditory system (cochlea) that affect the precise peripheral encoding of sound. Audiometry is the most common method used to assess hearing ability, and audiometric measures reflect the sensitivity of the peripheral auditory system to detect pure tones. Importantly, detection of pure tones does not substantively depend on higher-order cortical processing [11], meaning that audiometry can be reliably performed in adults with early dementia [12]. Age-related HL is the most common form of HL observed in adults and reflects progressive, irreversible damage to cells within the cochlea. The cochlea is particularly susceptible to damage over time given that most of the inner ear is post-mitotic (and hence incapable of regeneration), with risk factors for HL being age, race, sex, and noise exposure. Animal models of age-related HL as well as postmortem human temporal bone specimens from older adults demonstrate loss of sensory inner and outer hair cells, damage to the stria vascularis, and loss of cochlear nerve fibers [13]. The end result of accumulated damage to the cochlea (‘sensorineural HL’) is impaired encoding of sound and transmission of an impoverished and degraded auditory signal to the brain [14].
Effects of primary arterial hypertension on cochlear function
Published in Acta Oto-Laryngologica, 2021
We determined the air-conduction hearing thresholds between 0.125 and 16 kHz, and the bone-conduction hearing thresholds in both ears of all participants between 0.5 and 4 kHz. Audiometry was performed by an audiologist. A clinical audiometer (AC 40 model, Interacoustics, Otometrics, Taastrup, Denmark) and supra-aural Telephonics TDH-39P earphones were used for the conventional audiometry at 0.125, 0.25, 0.5, 1, 2, 4, 6, and 8 kHz (conventional thresholds). The ultra-high frequency (UHF) audiometry was performed with the same audiometer at 10, 12.5, 14, and 16 kHz and Koss HV/1A + circumaural earphones. Audiometer was calibrated with the ANSI S3.6-2004 standard. All hearing thresholds were determined by a standard Hughson-Westlake procedure (steps: 10 dB down, 5 dB up; 2 out of 3). All audiological tests were performed in a soundproof booth. The middle ear function was measured by tympanometry with a 226 Hz probe tone (AZ26 clinical impedance audiometer, Interacoustics, Assens, Denmark).
Related Knowledge Centers
- Acoustic Reflex
- Audiogram
- Audiology
- Audiometer
- Auditory Brainstem Response
- Auditory Cortex
- Otoacoustic Emission
- Equal-Loudness Contour
- Deafness
- Ear