Does Sound Conditioning Protect Against Temporary Hearing Damage
Condition: Hearing Loss, Noise-Induced
MeSH terms: Hearing Loss; Hearing Loss, Noise-Induced
Study type: Observational

Summary: 
      This research project will contribute to the research surrounding the effect on the ear after
      noise exposure. This ever-growing field of research has never been more applicable than now
      with the increase of recreational noise exposure. Noise is the leading cause of preventable
      hearing loss and excessive occupational noise along with recreational noise exposure can
      cause a devastating disability. The World Health Organisation (WHO) estimates 1.1 billion
      young people could be at risk of hearing loss due to unsafe listening practices.

      One of the mechanisms that could increase the resistance against noise induced hearing loss
      is 'sound conditioning'. Animal studies have found that prior exposure to low level noise
      over a period of a few weeks can 'condition' the ear. This conditioning then reduces the
      susceptibility to high level exposure i.e. strengthening the ear. In this study, the
      investigators aim to determine whether previous exposure to loud noise can condition the
      human ear, reducing the temporary hearing loss and temporary tinnitus ("ringing in the ear")
      that sometimes occurs after attending a loud nightclub or live music event.

      There are many implications of this research. For one it will allow us to understand more
      about the susceptibility to exposure of sounds and the resistance against noise induced
      hearing loss. This will mean that the investigators can enable appropriate interventions if
      necessary. For example, individuals who are more susceptible due to low prior exposure may be
      advised that they are at risk, and encouraged to use hearing protection. Being able to learn
      more about the impacts of noise with hearing and educate others such as understanding the
      impacts from high-level exposure.
    

Detailed description: 
      STUDY OBJECTIVES

      i) To identify if there is a relationship between previous sound exposure levels and TTS and
      tinnitus after a single loud noise event.

      STUDY DESIGN

      Type of Study: Basic Science Study, Between Groups Trial Aim: To investigate if previous
      sound conditioning reduces susceptibility to TTS and tinnitus when comparing to those without
      prior exposure.

      Purpose: To increase understanding on the effects of noise exposure. Duration: Data
      collection will be completed by February 2020 Participants: 40 normal hearing young (18-35)
      participants in good general health and fluent in English.

      Spilt into groups of two. One group (20, 10f:10m) with previous exposure i.e. nightclubs ++,
      the other group (20, 10f:10m) with less exposure measured through NESI.
    

Intervention name(s): Session One Test Battery; Session Two Test Battery; Session Three Test Battery
Intervention type(s): Diagnostic Test; Diagnostic Test; Diagnostic Test
Intervention description(s): Prior to noise exposure:
Test battery - High-frequency audiometry, Distortion Product Otoacoustic Emissions, Middle Ear Muscle Reflex, Speech-in-Noise test, Tinnitus Functional Index (Around 35 minutes with breaks if required)
Extended Frequency Audiometry (~ 8 min): Participants will be asked to press the button when they hear a sound through the headphones in a soundproof booth.
DPOAE (~ 5 min): A small tip will be placed in participants' ear and they will hear a sound. The tip measures a response from hair cells in the cochlea and they will not need to do anything.
MEMR (~ 8 min): A small tip placed in both ears and again a sound heard, however, this sound will gradually get louder until an involuntary muscle reflex is noted.
Speech-in-Noise Test (~ 5 min): Participants asked to repeat back a list of words as best as they can.
TFI (~ 8 min): Participants given a self-report sheet in which they have to fill out aspects of any tinnitus experienced.; Exposure at single loud music event (Important that this is part of participants' normal recreational routine, and specifically require that attendance is not prompted by participation in this study): Participants to use sound level meter provided from the Audiology Department at Charing Cross Hospital to measure sound levels inside the loud event.
Morning after exposure: Repeat test battery from session one - Ideally as soon as event is over.; 1 week later (recovery): Repeat test battery.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        40 Normal Hearing, Healthy 18-35 year olds.