This study is designed to measure the effects of a chewable Simethicone tablet taken by mouth on middle-ear pressure in adults with a common cold and evidence of abnormal middle-ear pressure. In children and adults, middle-ear diseases such as otitis media (the buildup of fluid within the middle ear) and a form of temporary hearing loss occur if the Eustachian tube does not open, does not open often enough or is always open. Simethicone, available over-the-counter under several brand names including Gas-X, may help break up the bubbles that may block the opening of the Eustachian tube in the back of the nose during a cold, allowing air to pass between the nose and middle ear. This study requires a single visit to the Middle Ear Physiology Laboratory in the Oakland section of Pittsburgh. If eligible for the study, Eustachian tube function testing will be done; the Simethicone tablet or placebo (a tablet that looks and tastes like the Simethicone tablet but has no active ingredient) will be given and Eustachian tube function testing repeated.

For the Eustachian tube function testing, the subject and a technician are seated comfortably within a pressure chamber, a room-like chamber in which the air pressure can be varied much like in an airplane or submarine. Middle ear pressure will be measured in each ear by tympanometry, a test done by inserting a small probe (an earplug attached to a rubber or plastic tube that measures ear pressure) half-way into the ear canal and changing the pressure in the probe. Then, microphones will be placed in the ear canals and a sound source placed into one nostril. The chamber pressure is then decreased and increased to various pressures and middle ear pressure is measured at these various pressures.

Inclusion Criteria:

• Age 18 to 50 years
• Healthy subjects other than current upper respiratory tract infection ("cold")
• Jackson Score of 6 on screening
• Subject reports symptom onset within 4 days of entry visit
• Unilateral or bilateral middle-ear pressure <-50 mmH2O

Exclusion Criteria:

• Otoscopic diagnosis of unilateral or bilateral otitis media
• Presence of tympanostomy tubes or tympanic membrane perforations bilaterally
• Asthma or any chronic medical disease or condition
• Use of an "over the counter" medicine within 24 hours of study or prescription within 4 weeks of the study day (except birth control)
• Use of an experimental drug within 3 months of study
• An unusual or allergic reaction to simethicone, food dyes, or preservatives
• Pregnancy or breast feeding
• Ear surgery other than tympanostomy tube insertion

Analysis done by ears with evaluable tests.

The subjects were assessed throughout the experimental procedure which lasted for 2 hours.