The mechanism of Continuous Positive Airway Pressure (CPAP) on hearing function in Obstructive Sleep Apnea (OSA) patients

Three participant cohorts will be enrolled: - Suspected OSA participants - Healthy Volunteers without CPAP - Non-OSA participants with Eustachian tube disorder What is involved: Suspected OSA participants: Part 1: Overnight Sleep Study -a battery of audiological assessment prior to sleep in the overnight sleep laboratory. This will be pure-tone audiometry, tympanometry, acoustic reflexes, otoacoustic emissions and subjective surveys on hearing and balance (12-item Spatial and Qualities of Hearing Scale (SSQ12); Hearing Handicap Inventory for Adults - Screening (HHIA-S) for participants under the age of 65 or Hearing Handicap Inventory for Elderly (HHIE-S) for participants over the age of 65; Dizziness Handicap Inventory (DHI); 4-item vestibular screening tool. This will be approximately 40 minutes - 1 hour in duration - During sleep, tympanometry will be completed approximately every 2 hours of sleep. If participants are prescribed CPAP therapy, tympanometry will be completed during sleep with CPAP approximately every 2-4 cmH20 CPAP increase. Participants with moderate OSA (AHI 15-30 events/hour) or severe OSA (AHI 31+ events/hour) are normally prescribed CPAP by the sleep physiologist. The overall sleep study will be approximately 10 hours including set up and 8 hours of sleep. - In the morning, the battery of audiological assessments will be completed. This will be pure-tone audiometry, tympanometry, acoustic reflexes, otoacoustic emissions. This will be approximately 30 minutes in duration. - An additional 40 minute audiological assessments will be untaken at 30-day follow up for participants who were issued CPAP. These would be the same assessments completed before sleep at baseline. Part 2: Daytime Eustachian Tube Evaluation: - Additional Eustachian Tube Evaluation- Up to 20 diagnosed severe OSA patients (AHI 31+ events/hour) recruited above will be asked to come to the University of Auckland Hearing and Tinnitus Clinic to complete Eustachian tube evaluation. This will involve pure-tone audiometry, tympanometry, Eustachian Tube function testing, acoustic reflexes, otoacoustic emissions and subjective surveys on hearing (12-item Spatial and Qualities of Hearing Scale (SSQ12)). CPAP will be applied while the patient is awake. Tympanometry, Eustachian tube function testing and video otoscopy (if available) will be repeated at CPAP pressure of 4cmH20, 10cmH20, 16cmH20 and 20cmH20. After CPAP, tympanometry, Eustachian tube function testing and acoustic reflexes will be repeated. This will take approximately 1 - 1 1/2 hours in duration during the day. As these patients would have been using CPAP therapy for awhile, up to 20 suspected OSA participants with high probability of severe (based from their sleep specialist assessment from the clinic letter) will also complete this Eustachian tube evaluation This visit can occur anytime after Part 1 at a convenient time for the participants. Healthy Participants: Part 1: Overnight Sleep Study -a battery of audiological assessment prior to sleep in the sleep laboratory. This will be pure-tone audiometry, tympanometry, acoustic reflexes, otoacoustic emissions and subjective surveys on hearing and balance (12-item Spatial and Qualities of Hearing Scale (SSQ12); Hearing Handicap Inventory for Adults - Screening (HHIA-S) for participants under the age of 65 or Hearing Handicap Inventory for Elderly (HHIE-S) for participants over the age of 65; Dizziness Handicap Inventory (DHI); 4-item vestibular screening tool. This will be approximately 40 minutes - 1 hour in duration - During sleep, tympanometry will be completed approximately every 2 hours of sleep. The overall sleep study will be approximately 10 hours including set up and 8 hours of sleep. - In the morning, the battery of audiological assessments will be completed. This will be pure-tone audiometry, tympanometry, acoustic reflexes, otoacoustic emissions. This will be approximately 30 minutes in duration. Part 2: Daytime Eustachian Tube Evaluation: - Additional Eustachian Tube Evaluation- Up to 20 healthy participants recruited above will be asked to come to the University of Auckland Hearing and Tinnitus Clinic to complete Eustachian tube evaluation. This will involve pure-tone audiometry, tympanometry, Eustachian Tube function testing, acoustic reflexes, otoacoustic emissions and subjective surveys on hearing (12-item Spatial and Qualities of Hearing Scale (SSQ12)). CPAP will be applied while the patient is awake. Tympanometry, Eustachian tube function testing and video otoscopy (if available) will be repeated at CPAP pressure of 4cmH20, 10cmH20, 16cmH20 and 20cmH20. After CPAP, tympanometry, Eustachian tube function testing and acoustic reflexes will be repeated. This will take approximately 1 - 1 1/2 hours in duration during the day. This visit can occur anytime after Part 1 at a convenient time for the participants. Non-OSA participants with Eustachian Tube Disorder: Part 1: Overnight Sleep Study - Not completed by this participant group Part 2: Daytime Eustachian Tube Evaluation: - Eustachian Tube Evaluation- Up to 20 Non-OSA participants with Eustachian tube disorder will be asked to come to the University of Auckland Hearing and Tinnitus Clinic to complete Eustachian tube evaluation. This will involve pure-tone audiometry, tympanometry, Eustachian Tube function testing, acoustic reflexes, otoacoustic emissions and subjective surveys on hearing (12-item Spatial and Qualities of Hearing Scale (SSQ12)). CPAP will be applied while the patient is awake. Tympanometry, Eustachian tube function testing and video otoscopy (if available) will be repeated at CPAP pressure of 4cmH20, 10cmH20, 16cmH20 and 20cmH20. After CPAP, tympanometry, Eustachian tube function testing and acoustic reflexes will be repeated. This will take approximately 1 - 1 1/2 hours in duration during the day. This visit can occur anytime after Part 1 at a convenient time for the participants.