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Trial registered on ANZCTR

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

Titles & IDs
Public title
Effect of programmed hearing aids on the brain: the CogniAid trial
Scientific title
Randomized controlled trial on the effect of programmed hearing aids on cognition in older New Zealanders
Secondary ID [1] 292337 0
Health Research Council (NZ) Reference 17/164
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Hearing loss 303883 0
Reduced cognitive reserve 303884 0
Condition category
Condition code
Ear 303246 303246 0 0
Other ear disorders

Study type
Description of intervention(s) / exposure
A double blind two arm 12-month randomised controlled trial comparing ‘usual care’ to a modified hearing aid fitting. The modified hearing aid fitting "CogniAid" settings:. The intervention group will receive processing with minimised signal distortion consisting of linear-slow processing (e.g. linear input-output processing, output limiting compression, non-adaptive manually selected directional microphone, moderate slow-acting noise reduction with manual program switching. The participant and clinician will decide the brand, model and technology level best suited on the basis of a hearing needs assessment. The aids will be programmed and matched to NAL-R linear hearing aid targets. If acoustic feedback occurs the ear-coupling system used (domes, ear moulds) will be modified for tighter acoustic seal before digital feedback methods are employed.
Intervention code [1] 298515 0
Treatment: Devices
Comparator / control treatment
The control group will receive current best practice hearing aid selection and fitting. The participant and clinician will decide the brand, model and technology level best suited on the basis of a hearing needs assessment. The selected aids Digital Signal processing (DSP) will emphasise audibility of sound using WDRC and signal “cleaning” to remove noise using fast-adaptive processing. The hearing aids will be programmed to the NAL-NL2 prescription procedure.
Control group

Primary outcome [1] 302625 0
The primary outcome measure will be the NIH toolbox age-adjusted composite cognitive score . These measures will be obtained using the iPad based NIH APP. The age adjusted Cognitive Function Composite score is comprised of several components, derived standard scores are based on the composite distribution and corrected relative age-related norms.
Timepoint [1] 302625 0
12 months
Secondary outcome [1] 336547 0
Secondary outcome measures will include changes in the NIH tool-box age adjusted composite cognitive score at 6 and 12 months.
Timepoint [1] 336547 0
6 and 12 months
Secondary outcome [2] 337071 0
HHIE-S, a hearing questionnaire.
Timepoint [2] 337071 0
6 and 12 months
Secondary outcome [3] 337072 0
WIN (Word in noise test).
Timepoint [3] 337072 0
6 and 12 months
Secondary outcome [4] 337073 0
MAPHAB a hearing questionnaire.
Timepoint [4] 337073 0
6 and 12 Months
Secondary outcome [5] 337074 0
Hours of hearing aid use determined using the on-board datalogging recordings of the hearing aids.
Timepoint [5] 337074 0
Continuous measurement for 12 months, the hearing aids record useage as hours or minutes, depending on model. The measure is continuous, hours of use will be recorded at 6 and 12 months.

Key inclusion criteria
Participants will be new hearing aid users aged 65 or older, and have below median NIH toolbox age-adjusted composite cognition scores
Minimum age
65 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Persons with median and greater NIH toolbox composite cognition scores will be excluded from the trial. Current hearing aid users will not be recruited. Persons with fluctuating hearing loss or fast-progressing ongoing otologic disease or requiring referrals to psychiatric or mental health services will be excluded. Persons with severe-profound hearing loss sufficient to make auditory cognition test materials inaudible will not be included. Persons unable to manually adjust aids using controls on the aid or remote control will be excluded.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation involvs contacting the holder of the allocation
schedule who is at central administration site. Participants will be randomly assigned 1:1 to intervention or control.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The randomization will be blocked and stratified to ensure ethnicity and age-adjusted cognition score are balanced in the two groups. The randomization lists will be created using SAS 9.4. Protocols will ensure adherence to allocation concealment. Participants, research assistants and statistician will be blinded to allocation until study completion.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Details of the individual’s hearing loss, hearing aids and datalogging with participant details will be entered into “NOAH” databases ( at the participating clinics. The NIH toolbox generates a spreadsheet of data for each test undertaken. This data will be duplicated and along with other test results and observations will be securely imported into an MS Excel database at the department of Epidemiology and Biostatistics at the University of Auckland. All analyses will be performed using SAS version 9.4 (SAS Institute Inc. Cary NC). Data analyses will be specified a priori in a statistical analysis plan prepared by the study statistician. The primary hypothesis of a difference in NIH toolbox age adjusted composite cognitive score at 12 months post randomization between the intervention and control group will be analysed using a general linear mixed model with age adjusted composite cognitive score as the continuous outcome and ethnicity, centre, baseline cognition score, hearing and group as explanatory variables. The “intention-to-treat” principle will be applied for all those completing 12 month follow up. Other outcomes will be tested by using nonparametric techniques, logistic regression, linear regression, or generalized linear mixed model, depending on the distribution of the variable.

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 9035 0
New Zealand
State/province [1] 9035 0

Funding & Sponsors
Funding source category [1] 296885 0
Government body
Name [1] 296885 0
Health Research Council
Address [1] 296885 0
Physical Address: Level 3 - ProCARE Building, Grafton Mews, at 110 Stanley Street (GPS: 50 Grafton Road), Grafton, Auckland 1010
Postal Address: PO Box 5541, Wellesley Street, Auckland 1141
Country [1] 296885 0
New Zealand
Primary sponsor type
The University of Auckland
The University of Auckland
Private Bag 92019
Auckland 1142
New Zealand.
New Zealand
Secondary sponsor category [1] 295892 0
Name [1] 295892 0
University of Canterbury
Address [1] 295892 0
20 Kirkwood Ave, Upper Riccarton, Christchurch 8041
Country [1] 295892 0
New Zealand

Ethics approval
Ethics application status
Ethics committee name [1] 298105 0
The University of Auckland Human Participants Ethics Committtee
Ethics committee address [1] 298105 0
The University of Auckland
Private Bag 92019
Auckland 1142
New Zealand.
Ethics committee country [1] 298105 0
New Zealand
Date submitted for ethics approval [1] 298105 0
Approval date [1] 298105 0
Ethics approval number [1] 298105 0

Brief summary
Untreated hearing loss speeds up age-related decline in our ability to process & understand information. Hearing aids may slow or halt this decline. Some technology used in hearing aids requires fast thinking that can be impaired with age. We will undertake a trial comparing standard hearing aid settings to those that have been set for slower processing of sound. In a case of “less is more” when our own processing of information becomes slower hearing aid processing also needs to slow down.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 76006 0
A/Prof Grant Donald Searchfield
Address 76006 0
The University of Auckland
Private Bag 92019
Auckland 1142
New Zealand.
Country 76006 0
New Zealand
Phone 76006 0
+64 9 923 6316
Fax 76006 0
Email 76006 0
Contact person for public queries
Name 76007 0
A/Prof Grant Donald Searchfield
Address 76007 0
The University of Auckland
Private Bag 92019
Auckland 1142
New Zealand.
Country 76007 0
New Zealand
Phone 76007 0
+64 9 923 6316
Fax 76007 0
Email 76007 0
Contact person for scientific queries
Name 76008 0
A/Prof Grant Donald Searchfield
Address 76008 0
The University of Auckland
Private Bag 92019
Auckland 1142
New Zealand.
Country 76008 0
New Zealand
Phone 76008 0
+64 9 923 6316
Fax 76008 0
Email 76008 0

No information has been provided regarding IPD availability
Summary results
No Results