{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/41713"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/41713","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Comparison of laboratory protocols for yielding improved estimates of hearing protection in field performance for use in standards development","abstract":"Federal law requires hearing protection device (HPD) manufacturers to provide attenuation ratings for use in estimating workers’ protection levels. These ratings, which are laboratory obtained, typically overestimate the actual protection levels achieved in the workplace. This research investigated laboratory protocols for yielding improved estimates of HPD in-field performance. Two experiments were conducted. The first was a pilot study developed by an American National Standards Institute (ANSI) working group. In this experiment, two types of earplugs were tested, a user-molded, malleable foam plug and a pre-molded, multi-sized rubber plug. Attenuation data (obtained using a psychoacoustical real-ear-attenuation-at-threshold measurement procedure) were collected across 10 subjects who entered the study as novice HPD users but were considered experienced HPD users in the latter half of the study. Four testing protocols involving two levels of HPDs, two levels of instruction-insertion techniques, and two levels of user experience were investigated. The same 10 subjects participated in all treatment conditions of the experiment. The second experiment involved similar protocols as the first; however, only one plug type was tested (the pre-molded, multi-sized rubber plug). Four testing protocols involving two levels of instruction-insertion techniques, two levels of user experience, and two levels of auditory feedback [fitting noise] were investigated. Forty subjects participated; each subject was tested in two treatment conditions. The attenuation results of each experiment were analyzed by statistical techniques. Statistical comparisons of results were made between the two experiments as well as between the experiments and selected field data. The major finding of the research was that fitting noise did not help subjects achieve higher attenuation [better protection] when consciously used for that purpose. Other findings indicated that novice subjects using only HPD manufacturer's instructions achieved attenuation that more closely represented the field attenuation than subjects tested under other conditions. However, the results were plug specific, in that no laboratory protocols yielded attenuation similar to the field data for the foam plug.","abstract_html":"Federal law requires hearing protection device (HPD) manufacturers to provide attenuation ratings for use in estimating workers’ protection levels. These ratings, which are laboratory obtained, typically overestimate the actual protection levels achieved in the workplace. This research investigated laboratory protocols for yielding improved estimates of HPD in-field performance. Two experiments were conducted. The first was a pilot study developed by an American National Standards Institute (ANSI) working group. In this experiment, two types of earplugs were tested, a user-molded, malleable foam plug and a pre-molded, multi-sized rubber plug. Attenuation data (obtained using a psychoacoustical real-ear-attenuation-at-threshold measurement procedure) were collected across 10 subjects who entered the study as novice HPD users but were considered experienced HPD users in the latter half of the study. Four testing protocols involving two levels of HPDs, two levels of instruction-insertion techniques, and two levels of user experience were investigated. The same 10 subjects participated in all treatment conditions of the experiment. The second experiment involved similar protocols as the first; however, only one plug type was tested (the pre-molded, multi-sized rubber plug). Four testing protocols involving two levels of instruction-insertion techniques, two levels of user experience, and two levels of auditory feedback [fitting noise] were investigated. Forty subjects participated; each subject was tested in two treatment conditions. The attenuation results of each experiment were analyzed by statistical techniques. Statistical comparisons of results were made between the two experiments as well as between the experiments and selected field data. The major finding of the research was that fitting noise did not help subjects achieve higher attenuation [better protection] when consciously used for that purpose. Other findings indicated that novice subjects using only HPD manufacturer's instructions achieved attenuation that more closely represented the field attenuation than subjects tested under other conditions. However, the results were plug specific, in that no laboratory protocols yielded attenuation similar to the field data for the foam plug.","abstract_has_math":false,"creators":["Richards, Michael Llewellyn"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Industrial and Systems Engineering","degree_department":"Industrial and Systems Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1991,"date_issued":"1991","date_published":"1991","updated_at":"2026-07-22T22:19:10Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-03172010-020615"],"render_values":[{"text":"etd-03172010-020615","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/41713","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Industrial and Systems Engineering"]},{"key":"dc:creator","label":"Author","values":["Richards, Michael Llewellyn"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:32:04Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:32:04Z","2010-03-17"]},{"key":"dc:date.issued","label":"Date","values":["1991"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Industrial and Systems Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-03172010-020615"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/41713"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Federal law requires hearing protection device (HPD) manufacturers to provide attenuation ratings for use in estimating workers’ protection levels. These ratings, which are laboratory obtained, typically overestimate the actual protection levels achieved in the workplace. This research investigated laboratory protocols for yielding improved estimates of HPD in-field performance. Two experiments were conducted. The first was a pilot study developed by an American National Standards Institute (ANSI) working group. In this experiment, two types of earplugs were tested, a user-molded, malleable foam plug and a pre-molded, multi-sized rubber plug. Attenuation data (obtained using a psychoacoustical real-ear-attenuation-at-threshold measurement procedure) were collected across 10 subjects who entered the study as novice HPD users but were considered experienced HPD users in the latter half of the study. Four testing protocols involving two levels of HPDs, two levels of instruction-insertion techniques, and two levels of user experience were investigated. The same 10 subjects participated in all treatment conditions of the experiment. The second experiment involved similar protocols as the first; however, only one plug type was tested (the pre-molded, multi-sized rubber plug). Four testing protocols involving two levels of instruction-insertion techniques, two levels of user experience, and two levels of auditory feedback [fitting noise] were investigated. Forty subjects participated; each subject was tested in two treatment conditions. The attenuation results of each experiment were analyzed by statistical techniques. Statistical comparisons of results were made between the two experiments as well as between the experiments and selected field data. The major finding of the research was that fitting noise did not help subjects achieve higher attenuation [better protection] when consciously used for that purpose. Other findings indicated that novice subjects using only HPD manufacturer's instructions achieved attenuation that more closely represented the field attenuation than subjects tested under other conditions. However, the results were plug specific, in that no laboratory protocols yielded attenuation similar to the field data for the foam plug."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["BTD"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Comparison of laboratory protocols for yielding improved estimates of hearing protection in field performance for use in standards development"]}]}],"canonical_facts":{"dc:contributor.department":["Industrial and Systems Engineering"],"dc:creator":["Richards, Michael Llewellyn"],"dc:date.accessioned":["2014-03-14T21:32:04Z"],"dc:date.available":["2014-03-14T21:32:04Z","2010-03-17"],"dc:date.issued":["1991"],"dc:description.abstract":["Federal law requires hearing protection device (HPD) manufacturers to provide attenuation ratings for use in estimating workers’ protection levels. These ratings, which are laboratory obtained, typically overestimate the actual protection levels achieved in the workplace. This research investigated laboratory protocols for yielding improved estimates of HPD in-field performance. Two experiments were conducted. The first was a pilot study developed by an American National Standards Institute (ANSI) working group. In this experiment, two types of earplugs were tested, a user-molded, malleable foam plug and a pre-molded, multi-sized rubber plug. Attenuation data (obtained using a psychoacoustical real-ear-attenuation-at-threshold measurement procedure) were collected across 10 subjects who entered the study as novice HPD users but were considered experienced HPD users in the latter half of the study. Four testing protocols involving two levels of HPDs, two levels of instruction-insertion techniques, and two levels of user experience were investigated. The same 10 subjects participated in all treatment conditions of the experiment. The second experiment involved similar protocols as the first; however, only one plug type was tested (the pre-molded, multi-sized rubber plug). Four testing protocols involving two levels of instruction-insertion techniques, two levels of user experience, and two levels of auditory feedback [fitting noise] were investigated. Forty subjects participated; each subject was tested in two treatment conditions. The attenuation results of each experiment were analyzed by statistical techniques. Statistical comparisons of results were made between the two experiments as well as between the experiments and selected field data. The major finding of the research was that fitting noise did not help subjects achieve higher attenuation [better protection] when consciously used for that purpose. Other findings indicated that novice subjects using only HPD manufacturer's instructions achieved attenuation that more closely represented the field attenuation than subjects tested under other conditions. 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