Tinnitus is the perception of sound when no actual external noise or sound is present. It is often referred to as “ringing” in the ears. I have even heard some people call it “head noises.” While ringing sounds are very common, many people will describe the sound they hear as buzzing, hissing, whistling, swooshing, and clicking. In some rare cases, tinnitus patients report hearing music. I hear about 2,000 crickets all going at once! 
Earwax (ear wax) is a natural substance secreted by special glands in the skin on the outer part of the ear canal. It repels water, and traps dust and sand particles. Usually a small amount of wax accumulates, dries up, and then falls out of the ear canal carrying with it unwanted particles. Under ideal circumstances, you should never have to clean your ear canals. The absence of ear wax may result in dry, itchy ears, and even infection. Ear wax may accumulate in the ear for a variety of reasons including; narrowing of the ear canal, production of less ear wax due to aging, or an overproduction of ear wax in response to trauma or blockage within the ear canal.

Ototoxic drugs can also cause subjective tinnitus, as they may cause hearing loss, or increase the damage done by exposure to loud noise. Those damages can occur even at doses that are not considered ototoxic.[30] Over 260 medications have been reported to cause tinnitus as a side effect.[31] In many cases, however, no underlying cause could be identified.[2]

If your doctor cannot find any medical condition responsible for your tinnitus, you may be referred to an otolaryngologist (commonly called an ear, nose, and throat doctor, or an ENT). The ENT will physically examine your head, neck, and ears and test your hearing to determine whether you have any hearing loss along with the tinnitus. You might also be referred to an audiologist who can also measure your hearing and evaluate your tinnitus.
Dr. Julie Prutsman’s team of audiologists offer a higher standard of expertise. She has been deeply involved with tinnitus for more than 15 years, long before effective treatments had been developed beyond hearing aids and maskers. Dr. Julie also studied under one of the industry’s most respected and leading medical experts, Dr. Pawel Jastreboff, and she has personally trained each and every one of her doctors.
Overdosing on certain prescription drugs, recreational drugs or alcohol. This can sometimes cause permanent damage to nerves that affect hearing. In some cases when a pregnant women uses drugs during pregnancy, this can cause tinnitus to develop in her child. Common drugs that might contribute to tinnitus include ototoxics, psychotropic drugs, aminoglycosides, certain antibiotics and vancomycin.
When a medication is ototoxic, it has a toxic effect on the ear or its nerve supply. In damaging the ear, these drugs can cause side effects like tinnitus, hearing loss, or a balance disorder. Depending on the medication and dosage, the effects of ototoxic medications can be temporary or permanent. More than 200 prescription and over-the-counter medicines are known to be ototoxic, including the following:
The treatment involves implanting a small electrode into a person’s neck near the vagus nerve. The patient then listens to specific tones that are paired with small electric pulses sent to the vagus nerve. This vagus nerve stimulation, coupled with the sound-based stimulation of the auditory cortex, can “turn down” the patient’s tinnitus. Though, Kilgard adds, “It’s not 100 percent yet.”
Tinnitus (pronounced "tin-it-tus") is an abnormal noise in the ear (note that it is not an "itis" -- which means inflammation). Tinnitus is common -- nearly 36 million Americans have constant tinnitus and more than half of the normal population has intermittent tinnitus.   Another way to summarize this is that about 10-15% of the entire population has some type of constant tinnitus, and about 20% of these people (i.e. about 1% of the population) seek medical attention (Adjamian et al, 2009). Similar statistics are found in England (Dawes et al, 2014) and Korea (Park and Moon, 2014).
Tinnitus affects males and females in equal numbers. It can affect individuals of any age, even children. Tinnitus, collectively, is a very common condition and estimated to affect approximately 10% of the general population. Rhythmic tinnitus occurs far less frequently than non-rhythmic tinnitus, accounting for approximately 1% of all cases of tinnitus and is considered relatively rare in the general population. The exact prevalence or incidence of rhythmic tinnitus is unknown. Rhythmic tinnitus due to pseudotumor and sinus wall anomalies is found most commonly in overweight women in their 3rd to 6th decade of life. The onset of tinnitus can be abrupt or develop slowly over time.
No matter what the cause, the condition interrupts the transmission of sound from the ear to the brain. Some of the neural circuits no longer receive signals. Strangely, this does not cause hearing loss. Instead, when neural circuits don’t receive stimulation, they react by chattering together, alone at first and then synchronous with each other. Once the nerve cells become hyperactive and occur at the same time, they simulate a tone the brain “hears” as tinnitus. Analogous to a piano, the broken “keys” create a permanent tone without a pianist playing the keys.
The important thing to remember about tinnitus is that the brain’s response to these random electrical signals determines whether or not a person is annoyed by their tinnitus or not. Magnetoencephalography (MEG, for short) studies have been used to study tinnitus and the brain. MEG takes advantage of the fact that every time neurons send each other signals, their electric current creates a tiny magnetic field. MEG allows scientists to detect such changing patterns of activity in the brain 100 times per second. These studies indicated tinnitus affects the entire brain and helps with understanding why certain therapies are more effective than others.
Inspection of the eardrum may sometimes demonstrate subtle movements due to contraction of the tensor tympani (Cohen and Perez, 2003). Tensor tympani myoclonus causes a thumping. Another muscle, the stapedius, can also make higher pitched sounds. See this page for more. Opening or closing of the eustachian tube causes a clicking.    The best way to hear "objective tinnitus" from the middle ear is simply to have an examiner with normal hearing put their ear up next to the patient.  Stethoscopes favor low frequency sounds and may not be very helpful.
This study has several strengths. It included a relatively large number of patients, reducing the possibility of bias by “masking” which treatment patients received, classifying participants according to the severity of their tinnitus and using highly standardised interventions. Also, the researchers used established scales to measure the severity of tinnitus and its impact on quality of life.
Some people experience a sound that beats in time with their pulse, known as pulsatile tinnitus or vascular tinnitus.[40] Pulsatile tinnitus is usually objective in nature, resulting from altered blood flow, increased blood turbulence near the ear, such as from atherosclerosis or venous hum,[41] but it can also arise as a subjective phenomenon from an increased awareness of blood flow in the ear.[40] Rarely, pulsatile tinnitus may be a symptom of potentially life-threatening conditions such as carotid artery aneurysm[42] or carotid artery dissection.[43] Pulsatile tinnitus may also indicate vasculitis, or more specifically, giant cell arteritis. Pulsatile tinnitus may also be an indication of idiopathic intracranial hypertension.[44] Pulsatile tinnitus can be a symptom of intracranial vascular abnormalities and should be evaluated for irregular noises of blood flow (bruits).[45]
Masking Devices. Similar to the white noise machines listed above, there are now masking devices that can be worn in the ear, just like a hearing aid, that do almost the same thing. They produce low-level white noise that can suppresses your tinnitus symptoms by training your brain to focus on them instead of the ringing in your ears. These are perfect if you can’t always have a white noise machine running near you.
The results were calculated using a measure called “effect size”, which is a way of quantifying the size of the difference between the two groups. For the difference in quality of life scores between groups, the effect size was calculated to be 0.24. This can be interpreted as a “small” effect. In other words, treatment including CBT gave a small improvement in quality of life compared with usual care.
There is a growing body of evidence suggesting that some tinnitus is a consequence of neuroplastic alterations in the central auditory pathway. These alterations are assumed to result from a disturbed sensory input, caused by hearing loss.[28] Hearing loss could indeed cause a homeostatic response of neurons in the central auditory system, and therefore cause tinnitus.[29]
Loud noise exposure: Being exposed to occupational loud noise on a regular basis from heavy equipment, chain saws or firearms is a common cause of tinnitus. However, even if you don’t work in a noisy environment, you can still suffer the effects of noise exposure by listening to loud music through headphones, attending live music performances frequently and engaging in noisy hobbies.