Marlin Johansson

Marlin Johansson

Affiliated to Research
Visiting address: Hälsovägen, Enheten för öron-,näs och halssjukdomar B61, 14186 Stockholm
Postal address: H9 Klinisk vetenskap, intervention och teknik, H9 CLINTEC Öron näs o halssjukd, 171 77 Stockholm

About me

  • I am a PhD student in medicine, audiology, at the ENT-division at CLINTEC,
    Stockholm, with a background in clinical audiology. I have a special interest
    in pediatrics and unilateral sensorineural hearing loss, hearing aids and
    other intervention options, newborn hearing-screening, neuroplasticity and
    inner ear mechanics.


  • The overall aim of my PhD project is to study the causes and mechanisms
    underlying congenital unilateral sensorineural hearing loss (uSNHL) and the
    effects of intervention.
    In the first PhD publication (Ear &
  • Hearing, 2020) we studied hearing aid
    outcomes in school-aged children with congenital uNSHL and demonstrate both
    hearing aid benefit and dis-benefit. The statistically significant benefit
    was found in one-to-one communication, based on child and parent
    questionnaires. Hearing aid dis-benefit was found for sound localization
    measured with eye-tracking in sound field. Neither significant hearing aid
    benefit nor dis-benefit existed for speech understanding in background
    noise/speech (sound field and questionnaires) or reverberation
    (questionnaires). A close relationship between neural maturation and aided
    sound localization was also found, indicating that hearing aids may be more
    efficient if fitted earlier in development, before the brain adapts to
    asymmetrical hearing.
    In the second PhD publication (Hearing Research, 2020) we studied heredity of
    transient evoked otoacoustic emissions (TEOAEs), that are recorded as part of
    the universal neonatal hearing-screening program. Before the study, one
    publication had estimated TEOAE heritability based on young adult twins’
    TEOAEs. In a large consecutive sample of neonatal twins (n = 454), we found
    that the TEOAEs at birth are largely inherited, perhaps more than for young
    adult twins. Additionally, we found that sex and ear differences existed at
    birth, and that the twin testosterone transfer hypothesis, that female twins
    with male co-twins would have masculinized TEOAEs, was not supported for
    neonatal twins.
    In my third PhD publication (Journal of Clinical Medicine, 2022) we study the
    etiologic background for congenital uSNHL and describe the auditory profiles
    of twenty consecutively recruited infants from the neonatal hearing-screening
    program in Region Stockholm. We present MRI, CMV and ABR results in the
    publication, and are currently also evaluating the twenty infant's genetic
    profiles and their auditory and speech-language development and hearing aid
    benefit longitudinally over the 2.5 first years of life.



  • Affiliated to Research, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, 2023-2025

Degrees and Education

  • Degree Of Doctor Of Philosophy, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, 2023

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