Impact of Auditory Environments on Pain in Fibromyalgia: a 4×4 Crossover Trial

NCT07037134 | Completed

• 1 other identifier: FIBRO-PAIN-SOUND-2025
• Study Type: interventional
• Target: 88
• Locations: 1 country
• Sites: 1

Brief Summary

This study examines whether different types of sounds can help reduce pain in people with fibromyalgia, a chronic condition that causes widespread pain and increased sensitivity to sensory experiences. Fibromyalgia affects approximately 2-3% of the global population and has limited treatment options. Recent research suggests that environmental sounds might have the capacity to influence pain perception, but their effects in chronic pain conditions remain largely unexplored. Such research could lead to new, non-invasive, sound-based approaches for managing fibromyalgia pain and inform the design of healthier acoustic environments for people with chronic pain conditions. The study will compare four different sound environments: natural soundscapes (like birdsong and rainfall), urban soundscapes (like traffic and background conversation), broadband sounds (white or pink noise), and silence (as a neutral/control condition with intended placebo effect). Researchers want to know if these different sound environments can change how people with fibromyalgia experience pain and if some environmental sounds might be more helpful than others. Each participant will experience all four sound conditions in a random order, with one session per week over four weeks. With this study design, each participant acts as their own control, which reduces differences between individuals and increases the reliability of the results. During each 20-minute session, participants will listen to the assigned sounds through a high-fidelity sound reproduction setup using headphones while lying comfortably on a padded therapy table in a controlled laboratory setting. Before and after each sound exposure, researchers measure pain intensity and sensitivity using standardized assessments to determine whether and how different sound environments, if any, might offer pain relief.

Conditions

Fibromyalgia Syndrome

Keywords

Acoustic environment; Audioanalgesia; Blank tape; Broadband noise; Chronic primary pain; Clinical trial; Crossover; Fibromyalgia; Natural sound; Pain modulation; Pink noise; Soundscape; Urban sound; White noise

Outcome Measures

Primary Outcomes (1)

• Pain intensity

  The primary outcome measure assesses acute changes in subjective pain intensity following each auditory intervention. Participants mark their current pain level on a 100-mm Visual Analog Scale anchored from "no pain" to "the worst pain imaginable". The scale is scored as the distance in millimeters from the left end, with lower scores corresponding to lower perceived pain.

  Change from immediately before to immediately after each 20-minute intervention session during each of the four crossover periods

Secondary Outcomes (4)

• Patient global impression of change

  Assessed immediately after each 20-minute intervention session during each of the four crossover periods

• Mechanical pain sensitivity

  Change from immediately before to immediately after each 20-minute intervention session during each of the four crossover periods

• Temporal summation of pain

  Change from immediately before to immediately after each 20-minute intervention session during each of the four crossover periods

• Pressure pain detection thresholds and intensity ratings

  Change from immediately before to immediately after each 20-minute intervention session during each of the four crossover periods

Other Outcomes (3)

• Somatosensory amplification

  Assessed at baseline

• Pain catastrophizing

  Assessed at baseline

• Connectedness to nature

  Assessed immediately after the final 20-minute intervention session, following completion of all other outcome assessments during the fourth crossover period (Week 4)

Study Arms (4)

Sequence NBPU

OTHER

Participants assigned to this sequence receive natural soundscape exposure in Week 1, broadband sound exposure in Week 2, placebo control (blank tape) in Week 3, and urban soundscape exposure in Week 4. Each session lasts 20 minutes, with one-week washout intervals between sessions.

Other: Natural soundscape exposure; Other: Urban soundscape exposure; Other: Broadband sound exposure; Other: Blank tape attention placebo control

Sequence UPBN

OTHER

Participants assigned to this sequence receive urban soundscape exposure in Week 1, placebo control (blank tape) in Week 2, broadband sound exposure in Week 3, and natural soundscape exposure in Week 4. Each session lasts 20 minutes, with one week washout intervals between sessions.

Other: Natural soundscape exposure; Other: Urban soundscape exposure; Other: Broadband sound exposure; Other: Blank tape attention placebo control

Sequence BUNP

OTHER

Participants assigned to this sequence receive broadband sound exposure in Week 1, urban soundscape exposure in Week 2, natural soundscape exposure in Week 3, and placebo control (blank tape) in Week 4. Each session lasts 20 minutes, with one week washout intervals between sessions.

Other: Natural soundscape exposure; Other: Urban soundscape exposure; Other: Broadband sound exposure; Other: Blank tape attention placebo control

Sequence PNUB

OTHER

Participants assigned to this sequence receive placebo control (blank tape) in Week 1, natural soundscape exposure in Week 2, urban soundscape exposure in Week 3, and broadband sound exposure in Week 4. Each session lasts 20 minutes, with one week washout intervals between sessions.

Other: Natural soundscape exposure; Other: Urban soundscape exposure; Other: Broadband sound exposure; Other: Blank tape attention placebo control

Interventions

Natural soundscape exposure OTHER

Participants receive a standardized 20-minute auditory exposure to curated natural soundscapes via high-fidelity open-back reference headphones powered by a DAC/amplifier and corrected for frequency response using calibration software. Participants are randomly assigned one of 22 recordings. Each includes 10-second fade-in/out effects and is calibrated to 45-55 dB. The stereo recordings (320-kbps MP3, 48 kHz/24-bit) feature biophony (e.g., bird vocalizations) and geophony (e.g., rainfall), free of urban sounds and selected for ecological validity based on predefined criteria: (i) recognizable/context-specific sounds; (ii) culturally neutral; (iii) foreground presence and depth; (iv) no prolonged silence; (v) no technical artifacts. During exposure, they lie supine in a 60° Fowler's position on a therapy table, with sensory input minimized through auditory isolation and controlled ambient conditions. The session involves active listening under continuous researcher supervision.

Also known as: Experimental intervention N

Sequence BUNP; Sequence NBPU; Sequence PNUB; Sequence UPBN

Urban soundscape exposure OTHER

Participants receive a standardized 20-minute auditory exposure to curated urban soundscapes, using the same equipment and technical specifications as all other intervention conditions. Each participant is randomly assigned one of 22 recordings, calibrated to 60-70 dB (Leq,20min). The recordings feature anthropophony (e.g., unintelligible background speech) and technophony (e.g., transportation-related sounds), free of natural sounds and selected for ecological validity based on the same predefined criteria as the natural soundscapes. To prevent semantic processing, participants are pre-screened and post-session reconfirmed to ensure they do not understand the languages used. During exposure, participants lie supine in a 60° Fowler's position on a therapy table, with sensory input minimized through auditory isolation and controlled ambient conditions. The session involves active listening and is conducted under continuous researcher supervision.

Also known as: Experimental intervention U

Sequence BUNP; Sequence NBPU; Sequence PNUB; Sequence UPBN

Broadband sound exposure OTHER

Participants receive a standardized 20-minute auditory exposure to broadband sounds (i.e., white or pink noise), using the same equipment and technical specifications as all other intervention conditions. Each participant is randomly assigned to one of the two noise types, with equal distribution across conditions. The stimuli are generated using professional audio software and calibrated to 50 dB (Leq,20min). During exposure, participants lie supine in a 60° Fowler's position on a therapy table, with sensory input minimized through auditory isolation and controlled ambient conditions. The session involves active listening and is conducted under continuous researcher supervision.

Also known as: Active comparator

Sequence BUNP; Sequence NBPU; Sequence PNUB; Sequence UPBN

Blank tape attention placebo control OTHER

Participants receive a standardized 20-minute exposure to blank audio (silence), using the same equipment and technical specifications as all other intervention conditions. At study onset, participants are informed they will hear a range of environmental sounds, including some that may be inaudible (i.e., present but beyond the range of human hearing). During the placebo condition, a blank recording is played, producing silence, while participants remain unaware of whether they are receiving an active or placebo stimulus. This attention-control condition ensures procedural consistency while delivering no auditory stimulation. During exposure, participants lie supine in a 60° Fowler's position on a therapy table, with sensory input minimized through auditory isolation and controlled ambient conditions. The session involves active listening and is conducted under continuous researcher supervision.

Also known as: Placebo comparator

Sequence BUNP; Sequence NBPU; Sequence PNUB; Sequence UPBN

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• A diagnosis of fibromyalgia syndrome, documented in the medical record provided by the participant prior to enrollment.
• Moderate or greater pain intensity during the preceding week, defined as a score higher than 3 on an 11-point Numeric Rating Scale.
• Normal hearing confirmed by a hearing test, defined as a mean threshold of ≤ 20 dB HL at 0.125, 0.25, 0.5, 1, 2, 4, 6, and 8 kHz.
• Ability to communicate in Spanish.
• Provision of signed written informed consent to participate in the research.

You may not qualify if:

• A diagnosis of misophonia or auditory processing disorders, as documented in the participant's medical record.
• Concurrent neuropathic or acute pain.
• Severe cognitive impairment, defined as a Mini-Mental State Examination score ≤ 17.
• Severe psychiatric disorders in the symptomatic phase.
• History of substance abuse in the past 12 months or current substance use disorder as reported by the participant.
• Changes in ongoing therapy during or within one month prior to study enrollment per participant self-reports.
• Central nervous system disorders.
• Any other serious or unstable medical condition that could interfere with study participation.
• Known allergies or hypersensitivity to study materials.
• Pregnancy, lactation, or being within three months postpartum at the time of study enrollment.

Sponsors & Collaborators

• Universidad de Granada: lead

Study Sites (1)

Faculty of Health Sciences, University of Granada

Granada, Granada, 18016, Spain

Location

MeSH Terms

Conditions

Fibromyalgia; Chronic Pain

Condition Hierarchy (Ancestors)

Muscular Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Neuromuscular Diseases; Nervous System Diseases; Pain; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• José Manuel Pérez Mármol, PhD

  Department of Physiotherapy, Faculty of Health Sciences, University of Granada

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: This study employs a triple-blind design: intervention administrator, outcome assessor, and data analyst will be fully masked, while participants will remain unaware (masked, not blinded) of the study hypotheses. The intervention administrator will be blinded to the audio content being delivered, as stimuli will be labeled with non-descriptive codes by a separate investigator. The outcome assessor will not be involved in the intervention and will be blinded to group allocation. Participants will be instructed not to disclose any intervention-related information. Any potentially unblinding data that could reveal group allocation will be masked before it reaches the outcome assessor. The data analyst will receive fully de-identified datasets, with groups labeled only as "Group A/B/C/D"; unblinding will occur only after all analyses have been completed and verified.
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Model Details: This study employs a randomized, triple-blind, placebo-controlled crossover design based on a 4×4 Williams Latin square. Each participant receives all four interventions in a randomized, balanced sequence across four periods, with one-week washout intervals separating each session to mitigate residual effects. The design ensures equal representation of each condition across periods and sequences (uniform within sequences and periods), controlling for first-order carryover effects. This model supports within-subject comparisons, minimizes interindividual variability and confounding, and improves statistical power and internal validity using robust outcome analysis via mixed-effects modeling.

Study Record Dates

• First Submitted: June 9, 2025
• First Posted: June 25, 2025
• Study Start: August 4, 2025
• Primary Completion: October 31, 2025
• Study Completion: October 31, 2025
• Last Updated: November 17, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR, ANALYTIC CODE
• Time Frame: Data requests may be submitted beginning 12 months after the article's publication. The data will remain available for up to 24 months thereafter. Requests for extended access will be considered on a case-by-case basis and may be granted if appropriately justified.
• Access Criteria: Data will be shared with qualified researchers who submit a methodologically sound proposal for analyses that align with the aims outlined in the approved application. Proposals should demonstrate scientific merit, methodological rigor, and the potential to advance understanding of chronic pain or auditory interventions. Requestors must sign a data sharing agreement that includes commitments to use the data only for approved purposes, implement appropriate data security measures, acknowledge the original study in any resulting publications, and share results with the original research team. For additional details or to initiate a request, please contact josemapm@ugr.es

Locations

ES (1)