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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Can sleep and cognition in healthy adult males be improved using an acoustic device?
Scientific title
The efficacy of acoustic tones in slow wave sleep enhancement and cognitive function in healthy adult males
Secondary ID [1] 290210 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Sleeping difficulties 300377 0
Impaired cognition 300378 0
Impaired slow wave sleep (SWS) 300379 0
Condition category
Condition code
Neurological 300242 300242 0 0
Studies of the normal brain and nervous system

Study type
Description of intervention(s) / exposure
On both conditions, participants are required to come into the Monash Sleep Laboratory for two nights. During their entire eight-hour sleep period, they are required to wear the deltaboost device. This is a device which measures EEG using a standard dry electrode. It is fitted by a trained PhD student or staff member, which typically involves cleaning the electrode site as per standard laboratory PSG and putting the headband onto the participant. On the first night, the device is worn so that the participants is acclimated to the device.

The headband of the device has three electrodes. These obtain an EEG signal and identify when the participant has reached N3 sleep (when the slow waves dominate).

On the experimental night, tones are administered through ear phones during N3 sleep. The volume of the tones is dependent on the individual. The tone volume is set prior to the experiment, and dependent on how sensitive the individual is to noise.

The tones are manually set through the DeltaBoost program and saved. The program is then used to write which file and volume the device uses. On the baseline nights, and if the participant is not flagged as sensitive, they will use a tone volume of 0.05-0.30. If the participants do flag as sensitive, the volume is reduced to 0.15. The DeltaBoost program is a custom built script that works with the DeltaBoost device.

Sensitivity is determined by running the DeltaBoost data through a MATLAB script, which identifies how easily the participant is aroused by the tones. On night 1, tones are played to the participants through the headphone during the first stage of SWS. The first tone is the lowest volume setting on the device (barely audible). Arousal is monitored on the EEG, and if no EEG-determined arousal is observed, the tone is switched up one level. This continues until an arousal is observed. The preceding tone before the arousal level is then used to determine the maximum volume for the experimental night. This procedure is automated by the DeltaBoost device.

The ideal tone is loud enough to invoke an EEG response (e.g., K complex) but not loud to enough to induce an arousal from sleep. The maximum tone is 72dB, which is indicated as 1 on the system. The typical tone is between 0.15 and 0.3. Tones are administered with a frequency of 1Hz during N3 only. On the control night, no tones are administered.

Each participant uses the same device for each visit. They are also allocated to their own rooms.

The order of the visits are randomised, with a one-week washout in between. Each visit consists of a consecutive 2 night, 2 day stay.

Intervention code [1] 295974 0
Treatment: Devices
Comparator / control treatment
During the control night, no tones are administered.
Control group

Primary outcome [1] 299719 0
The amount of delta waves throughout sleep, particularly during slow wave sleep.

The data is scored via polysomnography using the AASM scoring manual to determine the amount of slow wave sleep the participant has had during the night.
Timepoint [1] 299719 0
The entire eight-hour sleep period for the control and therapy nights are analysed.

Primary outcome [2] 300148 0
Amplitude of delta waves throughout sleep, particularly during slow wave sleep.

It is analysed via power spectral analyses (an automated Matlab script) to determine the amplitude of the delta waves.
Timepoint [2] 300148 0
The entire eight-hour sleep period for the control and therapy nights are analysed.
Secondary outcome [1] 327944 0
Cognitive functioning. Both executive and hippocampal functioning are measured using a variety of cognitive tests: paired associates task, psychomotor vigilance task (PVT), Karolinska drowsiness test (KDT), karolinska sleepiness scale (KSS), go nogo, groton maze task, n-back, tower of london, transverse patterning, verbal fluency and visual working memory task. There are alternate forms for all of the cognitive tasks.
Timepoint [1] 327944 0
The tests for alertness occur hourly, starting 1.5 hours after the participant's wake time, alternating between a single KSS (approx. 1 minute) and the full attention and vigilance test battery (10 minute PVT, 3 minute eyes open KDT, 2 minute eyes closed KDT & KSS).
.i.e. hour 1 is a single KSS, hour 2 is a attention and vigilance battery, hour 3 is a single KSS up until 9.5 hours after wake, when the study finishes.

The other cognitive tasks are split into two neurocognitive test batteries, administered 2 and 4 hours after wake time.
First test battery: visual working memory - capacity and filtering, approx. 10 minutes each, verbal fluency, approx 10 minutes, tower of london, approx 10 minutes.
Second test battery: go/nogo - approx 10 minutes, n-back, approx 10 minutes.

Key inclusion criteria
Healthy males
Between 35 and 50 years of age
Sleep efficiency of 80% or higher
Habitual bedtime between 10pm and 1am,
Fluent in English
Minimum age
35 Years
Maximum age
50 Years
Can healthy volunteers participate?
Key exclusion criteria
Does not have an average sleep duration between 5-6 hours or 7-9 hours
Has more than 2 naps per week
Scores more than 5 on the Pittsburgh Sleep Quality Index
Scores more than 10 on the Epworth Sleepiness Scale:
Regular shift workers and/or those who have traveled across time zones within the last 3 months
History of / current psychopathology (as determined by the Structured Clinical Interview for the DSM-V)
Family history of mood disorders
History of / current pain disorders, neurological disorders, concussion, or cardiac disorders
Has nystagmus, eye-tremor, or colour-blindness
Hearing impaired
Taking medication that affects the central nervous system
Consumes more than 14 standard drinks per week
Consumes more than 300mg of caffeine per day
Presents with alpha-delta sleep patterns

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
Intervention assignment
Other design features
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 294573 0
Government body
Name [1] 294573 0
Cooperative Research Centre (CRC) for Alertness, Safety and Productivity
Address [1] 294573 0
Ground Floor, Building 1

270 Ferntree Gully Road,

Country [1] 294573 0
Funding source category [2] 294659 0
Commercial sector/Industry
Name [2] 294659 0
Address [2] 294659 0
2 Canal Park, Cambridge, MA 02141, United States
Country [2] 294659 0
United States of America
Primary sponsor type
Clare Anderson
18 Innovation Walk (Building 17), Room 534
Monash University, Clayton, VIC 3800
Secondary sponsor category [1] 293515 0
Name [1] 293515 0
Sean Drummond
Address [1] 293515 0
18 Innovation Walk (Building 17)
Monash University, Clayton, VIC 3800
Country [1] 293515 0

Ethics approval
Ethics application status
Ethics committee name [1] 296006 0
Monash University Human Ethics Committee (MUHREC)
Ethics committee address [1] 296006 0
Room 111, Chancellery Building E.
24 Sports Walk, Clayton Campus, Monash University
Clayton, Victoria, 3800
Ethics committee country [1] 296006 0
Date submitted for ethics approval [1] 296006 0
Approval date [1] 296006 0
Ethics approval number [1] 296006 0

Brief summary
The deepest and most recuperative part of sleep, SWS, begins to decline from mid-adulthood. These reductions include both duration and the depth of SWS. This impairment may be linked to changes in cognitive performance.
Therefore, we hypothesize that enhancing SWS via acoustic stimuli leads to improvements in cognitive performance.
Trial website
Trial related presentations / publications
Diep, C., Ftouni, S., Drummond, S.P., Anderson, C. Enhancing slow wave activity via an automated phase locked acoustic stimulation. Poster. Annual Meeting of the Associated Professional Sleep Societies; 2017 June 3-7; Boston, USA.
Public notes

Principal investigator
Name 69250 0
A/Prof Clare Anderson
Address 69250 0
18 Innovation Walk (Building 17), Room 534
Monash University Clayton VIC 3800
Country 69250 0
Phone 69250 0
+61 3 9905 1714
Fax 69250 0
Email 69250 0
Contact person for public queries
Name 69251 0
A/Prof Clare Anderson
Address 69251 0
18 Innovation Walk (Building 17), Room 534
Monash University Clayton VIC 3800
Country 69251 0
Phone 69251 0
+61 3 9905 1714
Fax 69251 0
Email 69251 0
Contact person for scientific queries
Name 69252 0
A/Prof Clare Anderson
Address 69252 0
18 Innovation Walk (Building 17), Room 534
Monash University Clayton VIC 3800
Country 69252 0
Phone 69252 0
+61 3 9905 1714
Fax 69252 0
Email 69252 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary