IEM (In-Ear-Monitors) are listening devices that insert into the ear canal of the listener while providing a high level of isolation from external noises. In the professional/prosumer field, the shape and tips of the IEM are customized and molded into the shape of the user’s ear canals, providing an ultimate fit. On the consumer end, IEM usually come with standard fit kits containing silicon and/or foam tips in various sizes.

While some IEM are similar to traditional earbuds in the way they are worn (JAYS, Senneheiser, V-Moda etc.), many (Shure, UltimateEars, Westone etc.) are to be worn over the ear and behind the back, giving the user a “cordless” professional look.

Although putting on a pair of IEM may seem troublesome, the benefits of a sealed sound are plentiful. Besides having better sound quality in general, the careful use of IEM can also contribute to the prevention of hearing loss. Here’s why.

The seal of the ear canal from a pair of IEM blocks out external sound, thus reducing the total noise level exposed to the listener. In noisy environment, many with traditional earbuds tend to turn up the volume of their music in order drown out external noises. Under long-term exposure, this creates an extremely hazardous effect on one’s hearing. For example, on the bus, street traffic can reach up to 80 – 90 decibels (American Speech-Language-Hearing Association). In order to sufficiently hear one’s music over this level, one would have to crank their music up to at least 85 – 95 decibels. According to the ASHA, “Sounds louder than 80 decibels are considered potentially hazardous.” Needless to say, this is no way to enjoy music safely.

On the other hand, a pair of IEM when properly sealed can reduce up to 80% - 90% of ambient sound. With traffic noise out of the way, you can easily appreciate your music using only 2/3 – 3/4 of supposed volume. Just make sure to keep your eyes open so you don’t miss your stop!



In general, IEM do cost more than earbuds. But this is due to the cost in the required build material and the invested technology for the design of a good sound. Nonetheless, IEM also embody some negative qualities. For one, because the sound from IEM is reproduced right in the ear canal, excessive volume can cause more extensive damage to one’s hearing than from the same noise level coming out of speakers or other external sources. Moreover, with IEM plugged in and hearing blocked, one needs to be extra conscious of one’s surrounding environment for the sake of personal safety.


To conclude, like all things, the use of IEM comes with both advantages and disadvantages. From our perspective, IEM is a must if you want to safely enjoy music on the bus or in the subway. Unlike traditional earbuds, IEM gives you the option to lower the overall hearing level while providing a high-quality listening session. However, you must use them with care and let common sense guide you.


Pros:
- Provide safe listening volume in noisy environment
- Generally provide much better sound quality

Cons:
- Relatively expensive
- Need to be extra conscious of listening volume
- Need to be extra alerted towards surrounding safety



Written by Cecil L on August 12, 2008.
Visit http://www.asha.org/ for more information and resources on hearing safety.