Efficacy and Accuracy of an AI-Driven Sleep Earbud for Chronic Insomnia

This randomized, double-blind, two-sequence crossover clinical trial is designed to evaluate both the therapeutic efficacy of a closed-loop acoustic neuromodulation ear-worn device and the measurement accuracy of its embedded sensors against gold-standard laboratory diagnostics. The study architecture is executed across two distinct phases: a controlled laboratory phase followed by a naturalistic home-use extension.

Phase 1: Controlled Laboratory Assessment and Screening (Days 1-3)

Participants undergo consecutive three-night stays within a regulated hospital sleep medicine center.

Night 1 (Baseline and Diagnostic Screening): Participants are instrumented with a mobile polysomnography (PSG) system (SOMNOscreen™ plus) to capture baseline architecture across standard electrophysiological channels (EEG, EOG, EMG, ECG). This night serves to objectively screen for and exclude individuals presenting with hidden primary sleep disorders, specifically moderate-to-severe obstructive sleep apnea characterized by an Apnea-Hypopnea Index (AHI). No audio intervention is delivered.

Nights 2 and 3 (Randomized Crossover Window): Eligible participants who pass the diagnostic screen are randomized via sequential opaque envelopes into one of two intervention sequences (A-B or B-A). Allocation concealment is maintained by an independent unblinded study coordinator who programs the mobile application remotely, leaving the participant and data analyst blind to the track delivery. On one night, participants receive the experimental condition (AI-driven neuromodulation utilizing the NeuroRhythm algorithm to dynamically alter acoustic masking parameters based on real-time biometric feedback). On the alternate night, participants receive the sham condition (standard, non-adaptive acoustic music). Continuous PSG tracking runs concurrently both nights to allow epoch-by-epoch matrix synchronization between the earbud's internal sensor metrics and clinical hardware.

Neurocognitive and Subjective Profiling

On the mornings following Nights 1, 2, and 3, participants undergo standardized tracking procedures. Automated neurocognitive performance is mapped using the Cambridge Neuropsychological Test Automated Battery (CANTAB) touchscreen system to evaluate transient shifts in sustained attention, psychomotor alertness, and working memory efficiency linked to sleep structural changes. Subjective sleep depth, freshness, and hardware comfort metrics are gathered via morning clinical diaries.

Phase 2: Naturalistic Home Extension and Endpoint (Days 4-14)

Upon discharge from the sleep laboratory on Day 3, participants transition into a 14-day home-use window to assess the cumulative real-world utility of the intervention. Participants utilize the wearable earbud during sleep in their home environments according to their final laboratory sequence protocol assignment. Compliance, device tolerability, and subjective rest patterns are tracked daily via electronic logs. On Day 14, participants return for a final clinical endpoint visit to complete comprehensive psychometric re-evaluations, repeat the full-length neurocognitive battery (CANTAB), turn in all hardware, and execute the data collection confirmation logs.

Inclusion criteria

• Aged 18 to 55 years (inclusive).
• Able to understand the study protocol and voluntarily sign the informed consent form.
• Meets the diagnostic criteria for chronic insomnia disorder according to the International Classification of Sleep Disorders, Third Edition (ICSD-3) or DSM-5.
• Duration of insomnia symptoms is greater than 3 months but less than 2 years.
• Insomnia Severity Index (ISI) total score > 8 (indicating mild or greater clinical insomnia).
• Currently drug-free status: No use of any prescription or over-the-counter medications that affect sleep (including sedatives, hypnotics, antidepressants, antihistamines, or traditional Chinese medicine sleep aids) for at least 2 weeks (or more than 5 drug half-lives) prior to enrollment.
• Owns a smartphone and is capable of operating mobile applications to complete electronic questionnaires.
• Willing and able to tolerate wearing earplugs or earbuds during sleep.

Exclusion criteria

• Comorbid primary sleep disorders: Diagnosed via screening (STOP-Bang questionnaire) or polysomnography (PSG) with moderate-to-severe obstructive sleep apnea (OSA, defined as Apnea-Hypopnea Index $\\ge$ 15), narcolepsy, periodic limb movement disorder (PLMD), or other sleep disorders that could interfere with sleep quality assessments.
• Severe psychiatric or psychological conditions: A Patient Health Questionnaire (PHQ-9) score > 10 or a Generalized Anxiety Disorder scale (GAD-7) score > 10.
• History of schizophrenia, bipolar disorder, major depressive disorder, or active suicidal ideation.
• Active substance abuse or dependence: History of alcohol abuse (exceeding 14 standard drinks per week) or illicit drug use within the past 3 months.
• Comorbid somatic medical conditions: Severe or unstable physical illnesses (e.g., severe heart failure, malignant tumors, chronic pain) or neurological disorders known to impair sleep monitoring accuracy.
• Active ear diseases, ear canal discharge, structural abnormalities, or a history of related otologic surgeries that prevent or restrict earbud placement.
• Known history of hypersensitivity or allergic reactions to silicone or plastic materials.
• Disruptive lifestyle factors: Current engagement in shift work schedules or travel across more than 3 time zones within 2 weeks prior to study entry.
• Inability to provide independent informed consent or successfully complete cognitive testing due to profound language or cognitive barriers.