Evidence map›Paper›PMID 27762257›Full record

ArticleNoise & health

Soft tissue conduction as a possible contributor to the limited attenuation provided by hearing protection devices.

Shai Chordekar, Cahtia Adelman, Haim Sohmer, Liat Kishon-Rabin

Open access · goldAbstract read
In one paragraph

Article in Noise & health. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
0.2field-weighted citation impact, top 43% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed, 8 citations in OpenAlex.

  1. Article
  2. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors at 2 institutions in 1 country.

Shai ChordekarDepartment of Communication Disorders, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Cahtia AdelmanSpeech & Hearing Center, Hebrew University School of Medicine - Hadassah Medical Center, Jerusalem; Department of Communication Disorders, Hadassah Academic College, Jerusalem, Israel.
Haim SohmerDepartment of Medical Neurobiology (Physiology), Institute for Medical Research - Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Liat Kishon-RabinDepartment of Communication Disorders, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Tel Aviv University · ILHadassah Medical Center · IL

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

contextDamage to the auditory system by loud sounds can be avoided by hearing protection devices (HPDs) such as earmuffs, earplugs, or both for maximum attenuation. However, the attenuation can be limited by air conduction (AC) leakage around the earplugs and earmuffs by the occlusion effect (OE) and by skull vibrations initiating bone conduction (BC).

aimsTo assess maximum attenuation by HPDs and possible flanking pathways to the inner ear. SUBJECTS AND

methodsAC attenuation and resulting thresholds were assessed using the real ear attenuation at threshold (REAT) procedure on 15 normal-hearing participants in four free-field conditions: (a) unprotected ears, (b) ears covered with earmuffs, (c) ears blocked with deeply inserted customized earplugs, and (d) ears blocked with both earplugs and earmuffs. BC thresholds were assessed with and without earplugs to assess the OE.

resultsAddition of earmuffs to earplugs did not cause significantly greater attenuation than earplugs alone, confirming minimal AC leakage through the external meatus and the absence of the OE. Maximum REATs ranged between 40 and 46 dB, leading to thresholds of 46-54 dB HL. Furthermore, calculation of the acoustic impedance mismatch between air and bone predicted at least 60 dB attenuation of BC.

conclusionResults do not support the notion that skull vibrations (BC) contributed to the limited attenuation provided by traditional HPDs. An alternative explanation, supported by experimental evidence, suggests transmission of sound to inner ear via non-osseous pathways such as skin, soft tissues, and fluid. Because the acoustic impedance mismatch between air and soft tissues is smaller than that between air and bone, air-borne sounds would be transmitted to soft tissues more effectively than to bone, and therefore less attenuation is expected through soft tissue sound conduction. This can contribute to the limited attenuation provided by traditional HPDs. The present study has practical implications for hearing conservation protocols.

Indexed as

Ear Protective DevicesSoundAdultAuditory ThresholdBone ConductionFemaleHearing Loss, Noise-InducedHumansMaleVibrationYoung Adult

Identifiers

PMID27762257
PMCPMC5187656
OpenAlexW2538291823

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-SA
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.