Related Experiment Video
Updated: Jun 16, 2026
A Low Cost Setup for Behavioral Audiometry in Rodents
Published on: October 16, 2012
High frequency audiometric notch: an outpatient clinic survey
1Department of Audiovestibular Medicine, Queen Alexandra Hospital, Cosham, Portsmouth, PO6 3LY, UK. yaw@doctors.org.uk
Insights
High frequency notches (HFN) are often mistakenly linked to noise-induced hearing loss. This study found that HFNs are common in audiology patients, even without noise exposure, challenging their diagnostic value for hearing loss.
Area of Science:
- Audiology
- Otolaryngology
- Hearing Science
Background:
- High frequency notches (HFN) are frequently assumed to be indicative of noise-induced hearing loss (NIHL).
- This assumption may lead to misdiagnosis and inappropriate patient management.
- Understanding the prevalence of HFN in diverse clinical populations is crucial.
Purpose of the Study:
- To determine the prevalence of high frequency notches (HFN) in an audiovestibular medicine outpatient clinic.
- To assess the association between HFN and known risk factors for sensorineural hearing loss, particularly noise exposure.
- To challenge the diagnostic certainty of HFN for NIHL.
Main Methods:
- A consecutive series of 149 adult patients attending an audiovestibular medicine clinic were evaluated.
- Detailed clinical histories were obtained, focusing on neuro-otological symptoms, noise exposure (occupational and recreational), and other risk factors for hearing loss.
- Standard 8-frequency pure tone audiometry was performed to identify the presence and characteristics of HFNs.
Main Results:
- A significant proportion of patients (39.6%) exhibited HFNs without identifiable noise exposure or other known risk factors.
- HFNs were observed in the left ear (49.2%), right ear (25.4%), and bilaterally (25.4%).
- The majority of notches (71.6%) were shallow (less than 20 dBHL), with 4 kHz and 6 kHz being the most commonly affected frequencies.
Conclusions:
- High frequency notches are prevalent in audiology patients, independent of significant noise exposure.
- The presence of an HFN alone is not diagnostic of noise-induced hearing loss.
- A thorough clinical history remains essential for accurately diagnosing NIHL.
Abstract:
It is a common misconception that high frequency audiometric notches are diagnostic of noise induced hearing loss. The aim of this study was to identify the prevalence of high frequency notch (HFN) in an audiovestibular medicine outpatient clinic population at a district general hospital. One hundred and forty nine consecutive adult patients were assessed. According to standard practice at the audiovestibular clinic, a full clinical history with particular emphasis on neuro-otological symptoms, noise exposure, and medical risk factors for sensorineural hearing loss was taken. After standard 8-frequency pure tone audiometry, subjects were divided into those with HFN and those without. There were 84 (56%) females and 65 (44%) males with a mean age of 45 years (range: 19 to 91 years). A total of 39.6% had notches not attributable to noise (occupational or recreational) or any other known risk factor. In 29 (49.2%) and 15 (25.4%) the HFN was present in the left and right ear respectively whereas 15 (25.4%) were bilateral. The frequency least affected was 3 kHz while 4 kHz and 6 kHz were affected in almost equal proportions. In 53 ears (71.6%), the notch depth was less than 20 dBHL (10-19 dB) compared to 21 ears (28.4%) with a depth of 20 dBHL or more. This study concludes that high frequency notch without excessive noise exposure or any other known factor is common. It is neither diagnostic of, nor invariable with NIHL unless a convincing history of hazardous noise exposure is elicited from the history.
