Search results
Results from the WOW.Com Content Network
A sound attenuator, or duct silencer, sound trap, or muffler, is a noise control acoustical treatment of Heating Ventilating and Air-Conditioning (HVAC) ductwork designed to reduce transmission of noise through the ductwork, either from equipment into occupied spaces in a building, or between occupied spaces.
Cervicogenic headache is a type of headache characterized by chronic hemicranial pain referred to the head from either the cervical spine or soft tissues within the neck. [1] [2] The main symptoms of cervicogenic headaches include pain originating in the neck that can travel to the head or face, headaches that get worse with neck movement, and limited ability to move the neck.
Bone conduction is one reason why a person's voice sounds different to them when it is recorded and played back. Because the skull conducts lower frequencies better than air, people perceive their own voices to be lower and fuller than others do, and a recording of one's own voice frequently sounds higher than one expects (see voice confrontation).
Pain from sound sometimes radiates to the face, scalp, and neck. This may be due to the trigeminocervical complex in the brainstem, which integrates input from and output to various regions of the head and neck, including the middle ear. Of note, the tensor tympani muscle is innervated by the trigeminal nerve.
The head rests on the top part of the vertebral column, with the skull joining at C1 (the first cervical vertebra known as the atlas). The skeletal section of the head and neck forms the top part of the axial skeleton and is made up of the skull, hyoid bone, auditory ossicles, and cervical spine. The skull can be further subdivided into:
Some common symptoms and signs of mastoiditis include pain, tenderness, and swelling in the mastoid region. There may be ear pain , and the ear or mastoid region may be red (erythematous). Fever or headaches may also be present. Infants usually show nonspecific symptoms, including anorexia, diarrhea, or irritability. Drainage from the ear ...
In more than 40% of cases, however, the pain may be bilateral (both sides of the head), and neck pain is commonly associated with it. [46] Bilateral pain is particularly common in those who have migraine without aura. [33] Less commonly pain may occur primarily in the back or top of the head. [33]
Patients presenting with a headache originating at the posterior skull base should be evaluated for ON. This condition typically presents as a paroxysmal, lancinating or stabbing pain lasting from seconds to minutes, and therefore a continuous, aching pain likely indicates a different diagnosis. Bilateral symptoms are present in one-third of cases.