UMIN-CTR Clinical Trial

Public title

Do bedtime sounds work differently from person to person? A study in which each participant tries and compares several sounds

Acronym

The Sleep Sound Study (SONATA)

Scientific Title

Predicting Inter-Individual Variability in Response to Auditory Sleep-Induction Interventions: A Series of N-of-1 Trials

Scientific Title:Acronym

SONATA (Sleep-Onset N-of-1 Auditory Trial for individual Adaptation)

Region

Japan

Condition

Healthy adults with mild or greater insomnia symptoms (ISI-J score of 8 or more)

Classification by specialty

Medicine in general

Adult

Classification by malignancy

Others

Genomic information

NO

Narrative objectives1

To characterize inter-individual variability in sleep responsiveness to bedtime auditory interventions (pink noise, nature sounds, slow-tempo instrumental music, and silence) in healthy adults with mild sleep difficulty, using a within-person repeated-measures (N-of-1) design; and to develop a machine-learning model that predicts the optimal auditory condition for each individual from personal characteristics (personality traits, noise sensitivity, chronotype, and sleep profile), testing whether its predictive accuracy significantly exceeds the four-condition chance level of 25%. As a secondary aim, mediation analysis will decompose the pathway from the auditory intervention through shortened sleep onset latency to next-morning daytime function.

Basic objectives2

Efficacy

Basic objectives -Others

Trial characteristics_1

Exploratory

Trial characteristics_2

Developmental phase

Primary outcomes

The trial has a single primary outcome. The outcomes listed as key secondary outcomes are tested in a pre-specified hierarchical order after the primary outcome.

Subjective sleep onset latency (sSOL)
Measure: self-reported minutes to fall asleep, recorded with the Consensus Sleep Diary (Carney et al., 2012).
Time frame: every morning during the 28-day intervention period (Days 1-28).
Analysis: mixed-effects model (fixed effects: auditory condition and presentation order; random effect: participant), comparing each active condition (pink noise, nature sounds, slow-tempo instrumental music) with the silence control.
Success criterion: a reduction of 30% or more relative to the control condition, with p < 0.05.

Key secondary outcomes

Tested in a pre-specified hierarchical order; if a higher-ranked test is not significant, lower-ranked outcomes are reported as exploratory only.

1. ISI-J (Insomnia Severity Index, Japanese version; 7 items, 0-28; Bastien 2001) total score. Time frame: Weeks 0, 2 and 4; primary comparison is the Week 0 to Week 4 change. Analysis: paired comparison and mixed-effects model. Success: a reduction of 5 points or more (Benca 2024). Tested confirmatorily only if the primary outcome is significant.

2. Lapses on a 3-minute psychomotor vigilance task (PVT-3min, based on PVT-B; Basner & Dinges 2011) in the smartphone application. Time frame: every morning, Days 1-28. Analysis: mixed-effects model with Cohen's d and 95% confidence intervals.

3. Sleep-diary outcomes: sleep efficiency (sSE), wake after sleep onset (sWASO), subjective sleep quality and refreshment on waking (5-point scales). Time frame: every morning, Days 1-28.

4. Karolinska Sleepiness Scale (KSS). Time frame: every morning and during the day, Days 1-28.

5. Wearable-derived supporting measures: oSOL, oSE, oTST, oWASO, sleep-stage proportions, night-time HRV (RMSSD), resting heart rate and body movement. Time frame: every night, Days 1-28. Treated as surrogate measures, not used alone as evidence of an effect.

6. Pre-specified exploratory analyses: mediation of condition to sSOL to PVT lapses (bootstrap confidence intervals; between-person variability in proportion mediated); subjective-objective discrepancy (absolute sSOL minus oSOL) as a predictor of responsiveness; accuracy of the machine-learning model predicting each individual's optimal condition (4-class, chance 25%, target 65% or more, 5-fold cross-validation and hold-out); responder analysis (ISI-J reduction of 5 points or more and sSOL reduction of 30% or more).

Study type

Interventional

Basic design

n-of-1

Randomization

Randomized

Randomization unit

Individual

Blinding

Open -no one is blinded

Control

Self control

Stratification

Dynamic allocation

Institution consideration

Blocking

Concealment

No. of arms

4

Purpose of intervention

Treatment

Type of intervention

Other

Interventions/Control_1

Pink noise: 1/f noise with emphasized low frequencies, played automatically from bedtime until 30 minutes after sleep onset.

Interventions/Control_2

Nature sounds: rain and ocean waves, delivered in the same way as Arm 1.

Interventions/Control_3

Slow-tempo instrumental music: an arrangement of Pachelbel's Canon rendered with a piano timbre (fixed tempo of 60 BPM, no lyrics, seamlessly looped for 30 minutes). It was produced by the study team from public-domain sheet music via MIDI data and a piano sound source, and the audio file will be released as supplementary material at publication. Delivered in the same way as Arm 1.

Interventions/Control_4

Silence (control): ambient sound only. The application launches but plays no sound.

Interventions/Control_5

Interventions/Control_6

Interventions/Control_7

Interventions/Control_8

Interventions/Control_9

Interventions/Control_10

Age-lower limit

18

years-old

<=

Age-upper limit

75

years-old

>=

Gender

Male and Female

Key inclusion criteria

(1) Adults aged 18 to 75 years.

(2) Able to understand Japanese and to complete the questionnaires.

(3) Own a smartphone running iOS 16 or later, or Android 10 or later.

(4) A total score of 8 points or more on the Japanese version of the Insomnia Severity Index (ISI-J; Bastien et al., 2001), indicating at least mild insomnia.

(5) Willing to wear the wearable device loaned by the study team (wristband, watch, or upper-arm band type) every night and to listen to the assigned sound throughout the approximately four-week study period.

(6) Willing to complete the Consensus Sleep Diary and a 3-minute psychomotor vigilance task (PVT-3min) every morning, taking about six minutes in total, during the study period.

(7) Able to provide written informed consent, including electronic consent.

(8) No restriction on the area of residence.

Key exclusion criteria

(1) Diagnosed by a physician with a sleep disorder such as sleep apnea syndrome or restless legs syndrome.

(2) Currently taking hypnotics or psychotropic medication on a regular basis.

(3) Severe hearing impairment.

(4) Engaged in shift work, including night shifts, within the past month.

(5) Travelled across two or more time zones within the past month.

(6) Serious physical or psychiatric illness.

(7) Pregnant or possibly pregnant.

(8) Judged unsuitable for participation by the investigators for any other reason.

Target sample size

300

Name of lead principal investigator

1st name	Yasuyuki
Middle name
Last name	Taki

Organization

Institute of Development, Aging and Cancer, Tohoku University

Division name

Department of Aging Research and Geriatric Medicine

Zip code

980-8575

Address

4-1 Seiryo-Cho, Aoba-ku, Sendai, Japan

TEL

022-717-8582

Email

yasuyuki.taki.c7@tohoku.ac.jp

Name of contact person

1st name	Ryotaro
Middle name
Last name	Nakabayashi

Organization

Institute of Development, Aging and Cancer, Tohoku University

Division name

Department of Aging Research and Geriatric Medicine

Zip code

980-8575

Address

4-1 Seiryo-Cho, Aoba-ku, Sendai, Japan

TEL

022-717-8559

Homepage URL

Email

ryotaro.nakabayashi.e6@tohoku.ac.jp

Institute

Tohoku University

Institute

Department

Personal name

Organization

Self funding

Organization

Division

Category of Funding Organization

Self funding

Nationality of Funding Organization

Co-sponsor

Name of secondary funder(s)

Organization

Ethics Committee Tohoku University Graduate School of Medicine

Address

2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi

Tel

022-728-4105

Email

ec-med@grp.tohoku.ac.jp

Secondary IDs

NO

Study ID_1

Org. issuing International ID_1

Study ID_2

Org. issuing International ID_2

IND to MHLW

Institutions

東北大学加齢医学研究所（宮城県）

Date of disclosure of the study information

2026

Year

08

Month

03

Day

URL releasing protocol

Publication of results

Unpublished

URL related to results and publications

Number of participants that the trial has enrolled

Results

Results date posted

Results Delayed

Results Delay Reason

Date of the first journal publication of results

Baseline Characteristics

Participant flow

Adverse events

Outcome measures

Plan to share IPD

IPD sharing Plan description

Recruitment status

Preinitiation

Date of protocol fixation

2026

Year

06

Month

25

Day

Date of IRB

2026

Year

06

Month

25

Day

Anticipated trial start date

2026

Year

08

Month

03

Day

Last follow-up date

2028

Year

03

Month

31

Day

Date of closure to data entry

Date trial data considered complete

Date analysis concluded

Other related information

Registered date

2026

Year

08

Month

03

Day

Last modified on

2026

Year

08

Month

03

Day

Link to view the page

Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000071479