Preventing Noise Exposure in Farmworkers (POP)

February 11, 2026 updated by: Laura Coco, San Diego State University

This study will evaluate a farmworker-level hearing loss prevention training designed to improve hearing protection use among farmworkers exposed to hazardous occupational noise. The intervention consists of a culturally and linguistically adapted, Spanish-language digital training module paired with hands-on earplug fitting and coaching.

The primary goals of the study are to (1) assess the feasibility and acceptability of delivering the adapted training in community-based settings, and (2) estimate preliminary effectiveness using an objective measure of hearing protection fit. The study uses a single-arm, pre-post pilot design.

A small group of farmworkers will complete pre- and post-training assessments of earplug fit, as well as brief surveys assessing hearing protection knowledge, attitudes, and perceptions. Qualitative feedback will be collected to inform refinement of the training and guide future scale-up.

Results will inform the development of a subsequent multilevel intervention that integrates supervisor and organizational components.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Noise-induced hearing loss (NIHL) is a permanent occupational condition resulting from cumulative exposure to hazardous noise. Farmworkers are routinely exposed to high noise levels from agricultural equipment, yet hearing protection use remains low, particularly among Spanish-speaking workers. Prior hearing conservation efforts in agriculture have emphasized self-reported behaviors and have rarely incorporated objective outcome measures or culturally and linguistically adapted training approaches.

This study evaluates a farmworker-level hearing protection micro-training as part of a community-engaged pilot designed to inform subsequent multilevel intervention development. The study uses a single-arm, pre-post design and focuses on feasibility, acceptability, and preliminary effectiveness of the adapted training.

The intervention consists of a Spanish-language digital training module adapted through formative research with farmworkers and delivered with facilitated discussion and hands-on coaching in proper foam earplug insertion. Adaptations are informed by community input and documented using implementation science frameworks to support transparency and reproducibility.

Participants complete baseline assessments followed by a single training session and immediate post-training assessments. The primary effectiveness endpoint is an objective measure of hearing protection fit obtained through standardized fit-testing procedures. Additional measures assess short-term changes in hearing protection beliefs and implementation-related outcomes to characterize feasibility and acceptability of delivery in community-based settings.

This pilot is not designed to evaluate changes in long-term behavior or occupational noise exposure. Rather, results will be used to refine intervention content and delivery procedures, estimate preliminary effect sizes, and inform the design of a future cluster-randomized trial that incorporates supervisor and organizational-level components for hearing loss prevention in agricultural settings.

Study Type

Interventional

Enrollment (Estimated)

15

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Laura Coco, PhD, AuD
  • Phone Number: 16195943151
  • Email: lcoco@sdsu.edu

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Adults aged 18 years or older
  • Currently employed as a farmworker in agricultural settings with routine exposure to occupational noise
  • Able to understand and provide informed consent in Spanish or English

Exclusion Criteria:

  • Not currently employed as a farmworker
  • Medical or ear conditions that preclude safe use of foam earplugs (e.g., acute ear infection, recent ear surgery)
  • Inability to complete study procedures as determined by study staff

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Experimental: Farmworker Hearing Protection Training
Participants in this single-arm pilot study receive a one-time, farmworker-level hearing protection training. The intervention consists of a culturally and linguistically adapted Spanish-language digital training module paired with facilitated discussion and hands-on coaching in proper foam earplug insertion. All participants complete pre- and post-training assessments; there is no comparison or control group.
Behavioral: Farmworker Hearing Protection Training
This behavioral intervention is a brief, farmworker-level hearing protection training. The intervention includes a culturally adapted digital training module (novella-style) focused on noise-induced hearing loss prevention and correct foam earplug use, combined with hands-on earplug fitting and teach-back coaching. The training is delivered in a single session in a community-based setting.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Earplug Fit (Personal Attenuation Rating)
Time Frame: Pre-training and immediately post-training (single session)
Change in hearing protection fit measured using the Personal Attenuation Rating (PAR), an objective, device-generated fit-testing metric expressed in decibels (dB). PAR quantifies the level of noise attenuation achieved by an individual's foam earplug insertion. PAR values are obtained using standardized hearing protector fit-testing procedures conducted immediately before and immediately after the training session. PAR scores are reported in dB and typically range from 0 dB (no attenuation) to approximately 40 dB or greater depending on fit and device characteristics. Higher PAR values indicate greater attenuation and better earplug fit.
Pre-training and immediately post-training (single session)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Hearing Protection Beliefs and Attitudes
Time Frame: Pre-training and immediately post-training
Change in self-reported beliefs and attitudes toward hearing protection use, assessed using the 14-item Hearing Protection Beliefs scale. Items are rated on a 4-point Likert scale (1 = disagree to 4 = strongly agree) and summed after reverse-coding negatively worded items. Total scores range from 14 to 56, with higher scores indicating more favorable and accurate beliefs about hearing protection.
Pre-training and immediately post-training
Acceptability of the Hearing Protection Training
Time Frame: Immediately post-training
Participant-reported acceptability of the training assessed immediately post-training using the Acceptability of Intervention Measure (AIM). The AIM consists of 4 items rated on a 5-point Likert scale (1 = completely disagree to 5 = completely agree). Item responses are averaged to generate a mean score ranging from 1 to 5, with higher scores indicating greater perceived acceptability of the training.
Immediately post-training
Feasibility of the Hearing Protection Training
Time Frame: Immediately post-training
Participant-reported feasibility of the training assessed immediately post-training using the Feasibility of Intervention Measure (FIM). The FIM consists of 4 items rated on a 5-point Likert scale (1 = completely disagree to 5 = completely agree). Item responses are averaged to generate a mean score ranging from 1 to 5, with higher scores indicating greater perceived feasibility of the training.
Immediately post-training
Appropriateness of the Hearing Protection Training
Time Frame: Immediately post-training
Participant-reported appropriateness of the training assessed immediately post-training using the Intervention Appropriateness Measure (IAM). The IAM consists of 4 items rated on a 5-point Likert scale (1 = completely disagree to 5 = completely agree). Item responses are averaged to generate a mean score ranging from 1 to 5, with higher scores indicating greater perceived appropriateness of the training.
Immediately post-training

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

San Diego State University

Collaborators

National Institute on Deafness and Other Communication Disorders (NIDCD)

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2026

Primary Completion (Estimated)

January 1, 2031

Study Completion (Estimated)

January 1, 2031

Study Registration Dates

First Submitted

November 27, 2025

First Submitted That Met QC Criteria

November 27, 2025

First Posted (Actual)

December 9, 2025

Study Record Updates

Last Update Posted (Actual)

February 17, 2026

Last Update Submitted That Met QC Criteria

February 11, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRB-25-0158
  • 1K23DC022303-01A1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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