Plantronics are likely to be one of the names you think of when looking for audio headsets. They've been building the things for 45 years and proudly promote the fact that the first moon landing made use of their products.

In this review we look at the Plantronics CS70N, a device allowing wireless integration with your existing desk phone.

How We Tested
The Plantronics CS70N was connected to an existing Zultys ZIP4x5 VoIP phone in our office. With any phone system our major concerns are audio quality, ergonomics, ease of operation and construction.

What's Inside
The Plantronics CS70N is quite small and weighs only 23 grams. The casing is mainly rubber and plastic -- plastic for weight saving and rubber for comfort against the user's skin. Not being used to wearing such a device regularly, I found it surprisingly comfortable. The stem joining the main body to the earpiece and microphone arm flexes to accommodate varying ear sizes and also has a rotating joint which permits use on either ear. Replaceable ear inserts in both silicon and foam are supplied in varying sizes. The system was easy to set up with the manual providing very clear diagrams and written instructions. The headset has in-built activation and volume controls, though the volume buttons are overly stiff.

The silver and grey base-station has a number of controls for volume, compatibility adjustment and a switch used to indicate the presence of an optional handset-lifter attachment. The volume buttons are hidden behind and under the base-station which is neat, but possibly inconvenient.

As supplied, it is necessary to lift the receiver on your existing phone before pressing the call button on the headset to make or receive a call. To avoid the inconvenience of this double action, users can purchase a handset-lifter which is activated in response to the call button on the headset. There are LEDs to indicate power, active call, and headset charge status. The latter being placed poorly as it is somewhat hidden by the headset.

Most importantly, we found voice quality to be reasonable. The microphone was perhaps a little too sensitive as we found we were getting echoes when facing a wall at a distance of approximately two and a half metres. Voice quality sounded well at the other end of a call, using a second Zultys ZIP 4x5 phone. Speech sounded a bit tinny through the CS70N, but this is hardly surprising in such a small speaker and isn't a serious concern.

The manufacturer claims a range of up to 100 metres. We found that in a building where there are many obstructions the effective range was down to about 25 metres. This limitation was likely due to metallic barriers rather than concrete walls. The metallic coating on our office windows stopped the signals dead in their tracks. Needless to say, even a range of 25 metres would serve most offices admirably. There can be little doubt from the clarity of speech prior to the 25 metres mark that much greater ranges would be possible in areas free of metal barriers.

Verdict
Suddenly my desk phone has become both cordless and hands-free. Mind you this convenience does come at a price -- AU$579. Some may fall off their chairs when asked to pay this much for an attachment to an existing phone, but for those who spend all day on the phone and suffer the consequences of this the price will seem insignificant. Hands-free operation with a standard phone is not desirable over long periods.

I suspect a lot of people will be irritated by the need to take the existing phone off the hook as well as activating the headset when answering or initiating a call, but the optional automatic handset-lifter will alleviate this problem.

Overall this is a well designed unit. It is successful on a number of levels: attractiveness, comfort, ease-of-use and, of course effective audio transmission. If you spend hours on the phone you would do well to purchase one of these headsets. It comes with a one year return to reseller warranty and the Plantronics Web site offers FAQs and e-mail support. Purchasers can also seek support from the manufacturer with a toll free phone call.