At the end of this column, you’ll find my opinions on two relatively new iPhone-compatible headsets from Etymotic Research. But I intend to take the scenic route to get there, a route that takes us by some relevant and more general background information.

Background: The California "hands free" law and Bluetooth headsets

Beginning July 1, 2008, California (where I live) will join the ranks of those states where it is illegal to use a wireless phone while driving, unless you do it "hands-free." Actually, if you are under 18 years of age, the new law is even more restrictive: you "are prohibited from driving a motor vehicle while using a wireless telephone" under any circumstances.

This law will undoubtedly lead to a spike in sales of devices that permit hands-free use of a mobile phone. If you have an iPhone, the simplest and cheapest option, however, is to use the headset that came with the device. It’s a bit awkward: it’s not wireless and you should only use one earbud, so that you don’t block out noise that could be important in avoiding an accident � but it does the job. The other common options are to (1) buy a wired headset designed for phones, (2) use a GPS or similar device that includes a speaker and microphone that can connect to a mobile phone via Bluetooth, or (3) get a Bluetooth headset (such as Apple’s iPhone Bluetooth Headset).

I expect that the most popular solution, by far, will be Bluetooth headsets. That’s what I intend to use, at least for the moment. I already own one, an inexpensive Motorola device, but will be upgrading to a better quality one.

I confess that I have a love-hate relationship with these Bluetooth devices. I like the idea of the headsets � the ability to talk while you hands are busy with some other device, whether that be a steering wheel in your car or a keyboard in your office. But the reality is often quite different. Nevermind the general problems of getting a headset that feels comfortable on/in your ear or that provides a static-free noise-isolating sound. My concerns go beyond that.

I don’t often use a headset for phone calls and would probably only use one in the car (I don’t want to be one of those people that appear to be talking to themselves as they walk down the aisle of a supermarket). My infrequent use of a headset contributes to a series of related problems. First, I have to remember to take the device with me (unless I keep the headset and a charger in my car all the time). Second, I have to remember to keep the device charged. Third, I have to remember exactly how the device works. As to this last point, these headsets work via button presses (one long, two short, one long and one short, and so on); a given button press or button press sequence is used to turn the headset on, another to pair it with a phone, a third to answer a call, and yet others to adjust the volume and perform other functions. Given the occasionally long intervals between when I use the headset, I sometimes have to get out the manual to relearn which button press does what. Overall, it hasn’t been worth the bother. After the new law goes into effect, I’ll have to bother whether I like it or not.

By the way, dialing a phone number is not done hands-free, even if you are otherwise using a hands-free device. This brings up a somewhat murky area of the new California law. Can you dial a phone number while driving if you are otherwise using a Bluetooth headset? Or must you pull off the road to do so? From what I have read, there remains uncertainty about this. Regardless, a helpful work-around is voice-dialing. Unfortunately, as I have noted in previous columns, the iPhone does not yet support voice-dialing. Let’s hope the new iPhones (expected to arrive in June, by most accounts) will add this now needed-more-than-ever feature.

Background: Stereo headphones for the iPhone

Next, let’s shift gears to stereo headphones used for listening to music. Again, these are what you presumably already own; a pair comes with every iPhone or iPod. Unfortunately, the headphones that ship with Apple’s products are not especially good �� which is why there is such a huge market for third-party headphones. Heck, even Apple sells upgraded (in-ear) headphones for iPods.

Personally, I have long had a preference for Eytmotic Research’s headphones. It began with a pair of ER�4 headphones (which I got thanks to my Macworld colleague, Dan Frakes). These are the type of headphones that require you to insert the plugs into your ear � way in � deep enough to make a seal. Without the correct seal, you’ll miss out on much of the sound quality, especially the bass. Some people are uncomfortable, or even nervous, about using this type of headphone. It certainly takes a bit of time to get used to them. It can also be awkward if you want to share these headphones (no one wants to share your ear wax). And they do require some occasional maintenance, notably the periodic replacement of filters. Plus, they aren’t cheap.

But it’s all worth it. The sound improvement is that spectacular. First off, they are great at noise isolation. Even with the roar of a jet engine out your window, you’ll feel like you are in the quiet of your living room (well, almost). Then there’s the clarity. The sound is so crystal clear, especially the treble, that you’ll think the instruments are actually inside your head. You haven’t heard the tinkling of the ivories on recorded music, until you’ve heard them on these (or equal quality) headphones. Lesser headphones sound unacceptably muddy by comparison. The ER�4’s may sometimes seem to be a bit weak in bass response, but they are actually more accurate than the "boomy"-sounding cheaper headphones.

This is all why, when I first got my iPhone, I was disappointed that I had to put my ER�4’s aside. Why? Because they did not fit into the iPhone’s socket (as was true for virtually all headphones at the time). I eventually worked-around this by getting an adapter, but it was clumsy. Even with the adapter, I still didn’t have the microphone and remote-control buttons included with the iPhone’s native headphones. So I reluctantly gave up on my ER�4’s, at least most of the time, while I waited for Etymotic to come out with an iPhone-specific replacement.

Foreground: Two new headphones: a hit and a miss

First shown at Macworld Expo last January, I recently was (finally!) able to test out two new iPhone-compatible headphones from Etymotic Research.

The etyBLU ($129) is Etymotic’s answer to my quest for a Bluetooth headset needed to comply with California’s new "hands-free" law. Unfortunately, the etyBLU missed the mark for me. The sound quality was less than I expected; it seemed no better than many cheaper headsets I have tried. In addition, for some odd reason, getting a good ear seal was nearly impossible, particularly in my right ear. This was especially surprising given that the ear plugs were smaller than those on my ER�4’s, where I have no trouble making a seal. I am guessing it is due to the thicker circumference of the hard plastic that is immediately behind the plug. In any case, having this thing stuck in my ear, even when I was not using it (as would often be the case while driving), was not an appealing thought.

On the plus side, the etyBLU allows for recharging via USB, eliminating the need to carry around a separate device-specific power adapter when you travel (assuming you bring your laptop along). As for ease of use, the etyBLU was simpler and clearer than others I have tried. But using it still wasn’t as self-evident as I would have preferred. My search continues. Among the promising Bluetooth choices are the Aliph Jawbone and the Plantronics Discovery 925 or even Apple’s headset (although it has gotten lukewarm reviews overall). I’ll be checking them out before July rolls around.

The hf2 ($179) is Etymotic’s answer to my quest for a higher quality replacement for the stereo headphones that come with the iPhone. Here, Etymotic hit a bulls-eye. The hf2 has the needed slimmed-down plug that fits into the iPhone socket. And it has the microphone/remote control that allows you to pause/skip music and answer phone calls while using the headphones. And, best of all, the hf2’s sound quality compares very favorably to my ER�4’s. Happily, my search here is over.

Ted Landau is the founder of MacFixIt, and the author of Take Control of Your iPhone and other Mac help books.  You can .(JavaScript must be enabled to view this email address) Ted Landau or post your polite comments below.