An interventional study of Cochlear Stimulation System (CSS) in Healthy, sponsored by Mayo Clinic. Completed at 1 site in United States. Open to participants aged 21 Years to 75 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-12-30.
Sponsored by Mayo Clinic · Not applicable, Interventional, and Treatment
The purpose of this research is to develop a portable wearable hardware headset using a computer-based software that can establish the optimal stimulation parameters appropriate for medical and consumer environments for individuals with hearing impaired and normal hearing individuals.
Mayo Clinic is the lead sponsor of 3,218 studies on the registry; 670 are open to participants now.
Of its 445 completed or terminated interventional studies of FDA-regulated products, 313 (70%) have results posted.
Counted across the registry records on this site, refreshed daily.
- Employee of Mayo Clinic.
Exclusion Criteria:
Subjects with normal hearing will have a standard hearing test utilizing the cochlear stimulation system.
Device: Cochlear Stimulation System (CSS)
Subjects with bilateral hearing impairment will have a standard hearing test utilizing the cochlear stimulation system.
Device: Cochlear Stimulation System (CSS)
Subjects with asymmetrical hearing-impairment will have a standard hearing test utilizing the cochlear stimulation system.
Device: Cochlear Stimulation System (CSS)
Cochlear stimulation with surround sound and noise cancellation
Mean Change in Electric Current Subjects Indicated They Could Hear a Tone at Certain Frequencies
Evaluated by increasing the amplitude of the current input until the subject could hear a tone at 250 Hz, 500 Hz, 1,000 Hz, 2,000 Hz, 4,000 Hz, 8,000 Hz, 10,000 Hz, 12,500 Hz and 16,000 Hz. The mean electric current is reported in Milliampere (mA).
Time frame: Baseline, approximately 2 hours
Speech Intelligibility in Quiet Environment
Measured using the modified rhyme test (MRT) consisting of a set of 50 six-item wordlist. Each word list contains single syllable words with a consonant-vowel-consonant sound sequence. Subjects completed electrical word recognition testing in a quiet environment. Electrodes were placed at 3 unique locations (forehead, mastoid, neck) to measure how well speech could be delivered to the subject through the skin electrodes in a manner that would allow subjects to recognize words in a quiet environment. There were 2 experiments done for speech intelligibility. The first involved 20 subjects (outcome 2) and aimed to assess speech intelligibility performance in a basic, quiet environment without background noise. This phase focused on evaluating the fundamental hearing performance. Once it was established that speech intelligibility was satisfactory with electrical stimulation, we proceeded to test an additional 30 subjects in both quiet and noisy environments (outcome 3).
Time frame: Baseline, approximately 2 hours
Speech Intelligibility in Quiet and Noisy Environments
Measured using the modified rhyme test (MRT) consisting of a set of 50 six-item wordlist. Each word list contains single syllable words with a consonant-vowel-consonant sound sequence. Subjects completed electrical word recognition testing in a quiet, then a noisy environment. Electrodes were placed at 3 unique locations (mastoid, wrist, back) to measure how well speech could be delivered to the subject through the skin electrodes in a manner that would allow subjects to recognize words in a quiet and noisy environment. There were 2 experiments done for speech intelligibility. The first involved 20 subjects (outcome2) and aimed to assess speech intelligibility performance in a basic, quiet environment without background noise. This phase focused on evaluating the fundamental hearing performance. Once it was established that speech intelligibility was satisfactory with electrical stimulation, we proceeded to test an additional 30 subjects in both quiet and noisy environments (outcome3)
Time frame: Baseline; approximately 2 hours
| Milestone | Normal Hearing Subjects | Bilateral Hearing Impaired | Asymmetrical Hearing-impaired |
|---|---|---|---|
| Started | 55 | 5 | 8 |
| Completed | 55 | 5 | 8 |
| Not completed | 0 | 0 | 0 |
Evaluated by increasing the amplitude of the current input until the subject could hear a tone at 250 Hz, 500 Hz, 1,000 Hz, 2,000 Hz, 4,000 Hz, 8,000 Hz, 10,000 Hz, 12,500 Hz and 16,000 Hz. The mean electric current is reported in Milliampere (mA).
| mA | Normal Hearing Subjects | Bilateral Hearing Impaired | Asymmetrical Hearing-impaired |
|---|---|---|---|
| 250 Hz | 2.16 ± 1.07 | 2.88 ± 1.44 | 2.88 ± 0.97 |
| 500 Hz | 1.86 ± 1.62 | 2.93 ± 1.42 | 2.40 ± 1.14 |
| 1,000 Hz | 1.09 ± 0.42 | 1.75 ± 0.53 | 1.70 ± 0.42 |
| 2,000 Hz | 1.29 ± 0.43 | 1.77 ± 0.81 | 1.71 ± 0.60 |
| 4,000 Hz | 1.56 ± 0.67 | 3.50 ± 2.35 | 1.84 ± 0.68 |
| 8,000 Hz | 1.71 ± 0.79 | 2.25 ± 1.06 | 3.00 ± 1.76 |
| 10,000 Hz | 1.97 ± 1.06 | 3.25 ± 1.06 | 3.96 ± 2.51 |
| 12,500 Hz | 2.29 ± 1.32 | 6.00 ± 3.46 | 3.67 ± 1.47 |
| 16,000 Hz | 2.94 ± 1.30 | 5.00 ± 0.00 | 4.21 ± 1.25 |
Measured using the modified rhyme test (MRT) consisting of a set of 50 six-item wordlist. Each word list contains single syllable words with a consonant-vowel-consonant sound sequence. Subjects completed electrical word recognition testing in a quiet environment. Electrodes were placed at 3 unique locations (forehead, mastoid, neck) to measure how well speech could be delivered to the subject through the skin electrodes in a manner that would allow subjects to recognize words in a quiet environment. There were 2 experiments done for speech intelligibility. The first involved 20 subjects (outcome 2) and aimed to assess speech intelligibility performance in a basic, quiet environment without background noise. This phase focused on evaluating the fundamental hearing performance. Once it was established that speech intelligibility was satisfactory with electrical stimulation, we proceeded to test an additional 30 subjects in both quiet and noisy environments (outcome 3).
| percentage of correct scores on MRT | Normal Hearing Subjects | Bilateral Hearing Impaired | Asymmetrical Hearing-impaired |
|---|---|---|---|
| Forehead | 84.38 ± 14.9 | — | — |
| Mastoid | 94.06 ± 5.9 | — | — |
| Neck | 84.06 ± 11.6 | — | — |
Measured using the modified rhyme test (MRT) consisting of a set of 50 six-item wordlist. Each word list contains single syllable words with a consonant-vowel-consonant sound sequence. Subjects completed electrical word recognition testing in a quiet, then a noisy environment. Electrodes were placed at 3 unique locations (mastoid, wrist, back) to measure how well speech could be delivered to the subject through the skin electrodes in a manner that would allow subjects to recognize words in a quiet and noisy environment. There were 2 experiments done for speech intelligibility. The first involved 20 subjects (outcome2) and aimed to assess speech intelligibility performance in a basic, quiet environment without background noise. This phase focused on evaluating the fundamental hearing performance. Once it was established that speech intelligibility was satisfactory with electrical stimulation, we proceeded to test an additional 30 subjects in both quiet and noisy environments (outcome3)
| percentage of correct MRT scores | Normal Hearing Subjects | Bilateral Hearing Impaired | Asymmetrical Hearing-impaired |
|---|---|---|---|
| Mastoid-Quiet Environment | 93.86 ± 8.2 | — | — |
| Wrist-Quiet Environment | 93 ± 9.7 | — | — |
| Back-Quiet Environment | 93.83 ± 10.2 | — | — |
| Mastoid-Noisy Environment | 85.37 ± 11.7 | — | — |
| Wrist-Noisy Environment | 86 ± 12.7 | — | — |
| Back-Noisy Environment | 82.07 ± 12.5 | — | — |
Collected over Adverse events were collected from the time of informed consent through study completion, approximately 2 hours.. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Normal Hearing Subjects | 0/55 (0%) | 0/55 (0%) | 0/55 (0%) |
| Bilateral Hearing Impaired | 0/5 (0%) | 0/5 (0%) | 0/5 (0%) |
| Asymmetrical Hearing-impaired | 0/8 (0%) | 0/8 (0%) | 0/8 (0%) |
| Age, Continuous(years) | Normal Hearing Subjects | Bilateral Hearing Impaired | Asymmetrical Hearing-impaired | Total |
|---|---|---|---|---|
| Mean | 33.78 ± 9.33 | 56.8 ± 11.39 | 59 ± 13.44 | 38.51 ± 13.84 |
| Sex: Female, Male(Participants) | Normal Hearing Subjects | Bilateral Hearing Impaired | Asymmetrical Hearing-impaired | Total |
|---|---|---|---|---|
| Female | 31 | 3 | 3 | 37 |
| Male | 24 | 2 | 5 | 31 |
| Ethnicity (NIH/OMB)(Participants) | Normal Hearing Subjects | Bilateral Hearing Impaired | Asymmetrical Hearing-impaired | Total |
|---|---|---|---|---|
| Hispanic or Latino | 11 | 2 | 2 | 15 |
| Not Hispanic or Latino | 37 | 2 | 5 | 44 |
| Unknown or Not Reported | 7 | 1 | 1 | 9 |
| Race (NIH/OMB)(Participants) | Normal Hearing Subjects | Bilateral Hearing Impaired | Asymmetrical Hearing-impaired | Total |
|---|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 | 0 |
| Asian | 6 | 0 | 0 | 6 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 | 0 |
| Black or African American | 3 | 1 | 0 | 4 |
| White | 38 | 3 | 8 | 49 |
| More than one race | 0 | 0 | 0 | 0 |
| Unknown or Not Reported | 8 | 1 | 0 | 9 |
| Region of Enrollment(participants) | Normal Hearing Subjects | Bilateral Hearing Impaired | Asymmetrical Hearing-impaired | Total |
|---|---|---|---|---|
| United States | 55 | 5 | 8 | 68 |
Documents are hosted by the registry — open the source record to download them.
This study is completed, as verified in Dec 2025. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Mayo Clinic