First of all: is it true that earwax (or cerumen) comes out naturally from the ear?
Yes it is. The purpose of ear wax is to trap particles that may enter the ear from the outside, and bring them out of the ear canal.
From S. Gelfand - Essentials of audiology
Cerumen is a waxy substance that is supposed to be in the ear canal, where it serves lubricating and cleansing functions and also helps to protect the ear from bacteria, fungi, and insects. The cerumen is produced by glands in the cartilagenous portion of the ear canal and migrates out over time.
Impacted cerumen is an accumulation of wax in the ear canal that interferes with the flow of sound in the eardrum. Impacted cerumen occurs naturally in many patients who produce excessive amount of cerumen, which builds up over time. It is also the fate of many Q-tip wielding patients who inadvertently pack cerumen farther back into the canal (and frequently against the eardrum) in an ironic attempt to clean their ears
Should earwax be removed?
The American Academy of Otolaryngology says not to, unless it presents a medical risk.
From their website
When should the ears be cleaned?
Under ideal circumstances, the ear canals should never have to be cleaned. However, that isn’t always the case. The ears should be cleaned when enough earwax accumulates to cause symptoms or to prevent a needed assessment of the ear by your doctor. This condition is all cerumen impaction, and may cause one or more of the following symptoms:
Earache, fullness in the ear, or a sensation the ear is plugged
Partial hearing loss, which may be progressive
Tinnitus, ringing, or noises in the ear
Itching, odor, or discharge
Various methods exist to remove cerumen. Wikipedia lists:
A number of softeners are effective; however, if this is not sufficient, the most common method of cerumen removal is syringing with warm water. A curette method is more likely to be used by otolaryngologists when the ear canal is partially occluded and the material is not adhering to the skin of the ear canal. Cotton swabs, on the other hand, push most of the earwax further into the ear canal and remove only a small portion of the top layer of wax that happens to adhere to the fibres of the swab.
There is also quite a bit of literature on the matter.
This paper (bear in mind that it was written in 1990, so it may not be reflecting the current situation), surveys 289 practitioners about "the methods of removing ear wax [...] and the incidence of associated complications".
Ear wax removal: a survey of current practice - Sharp et al. 1990
The 289 replies received (92% of the study group) indicated that each doctor saw an average of nine patients (range five to 50 or more) requesting the removal of ear wax per month (table I). The initial medical assessment was made by 179 general practitioners
(62%). No medical assessment was made by 23 (8%); these patients were referred directly to the practice nurse. The remaining 87 (30%) offered examination by either the doctor or nurse.
The most used method of wax removal was syringing a ceruminolytic agent (something that melts the wax, such as oil or bicarbonate or special formulations), either done directly by the doctor or by a nurse.
The paper reports that
Complications had been experienced by 105 practitioners (38%) and included perforation, canal lacerations, and failure of wax removal. The removal of occlusive wax improved hearing by a mean of 5 dB over the frequencies analysed.
and concludes that:
About 44000 ears are syringed each year in the area and complications requiring specialist referral are estimated to occur in 1/1000 ears syringed. The incidence of complications could be reduced by a greater awareness of the potential hazards, increased instruction of personnel, and more careful selection of patients.
A more recent systematic review of clinical trials can be found in
The safety and effectiveness of different methods of earwax removal: a systematic review and economic evaluation. - Clegg et al. 2010
They analyzed 22 randomised controlled trials and 4 controlled clinical trials, using different types of softeners, with or without irrigation.
They report that:
On measures of wax clearance Cerumol, sodium bicarbonate, olive oil and water are all more effective than no treatment; triethanolamine polypeptide (TP) is better than olive oil; wet irrigation is better than dry irrigation; sodium bicarbonate drops followed by irrigation by nurse is more effective than sodium bicarbonate drops followed by self-irrigation; softening with TP and self-irrigation is more effective than self-irrigation only; and endoscopic de-waxing is better than microscopic de-waxing. AEs (adverse events) appeared to be minor and of limited extent. Results of the exploratory economic model found that softeners followed by self-irrigation were more likely to be cost-effective [24,433 pounds per quality-adjusted life-year (QALY)] than softeners followed by irrigation at primary care (32,130 pounds per QALY) when compared with no treatment. Comparison of the two active treatments showed that the additional gain associated with softeners followed by irrigation at primary care over softeners followed by self-irrigation was at a cost of 340,000 pounds per QALY. When compared over a lifetime horizon to the 'no treatment' option, the ICERs for softeners followed by self-irrigation and of softeners followed by irrigation at primary care were 24,450 pounds per QALY and 32,136 pounds per QALY, respectively.
They conclude that:
Although softeners are effective, which specific softeners are most effective remains uncertain. Evidence on the effectiveness of methods of irrigation or mechanical removal was equivocal. Further research is required to improve the evidence base, such as a RCT incorporating an economic evaluation to assess the different ways of providing the service, the effectiveness of the different methods of removal and the acceptability of the different approaches to patients and practitioners.