heart rate monitors synching w/computer

[Oliver]

You got me curious here.  I had a quick look around the web, and it seems that 'dynamic speakers' are just plain or garden variety, permanent magnet/electromagnetic voicecoil speakers.  The other main type of speaker used in audio reproduction is an electrostatic speaker.  I personally think the term 'dynamic speaker' is daft, but then they didn't ask me when they made it.  There is another type of magnetic speaker, which uses opposing electomagnetic fields, but these are uncommon today.  There are also other types of speakers, but they are not really worth a mention.

I believe the wrist watch communicates to the monitor via magnetic field transmission.  The wrist watch should be able to receive a signal from a speaker in a similar fashion.  I suspect the monitor comes with PC software, which your doctor probably neglected to issue to you.  I had a look at an apparrently similar product here.

[Oliver]

Most speakers use magnetic fields.  Tweaters may be piezoelectric, but not likely a woofer.

Magnetic antennae are usually just based on a conductive loop, using inductive pickup.  There are other ways to detect fields, though I guess it's just the inductive loop.

I would think that explaining technology doesn't usually help any marketing efforts, so they wouldn't bother.  It might just frighten some people to think of these fields within close proximity.

Hope the heart gets better.  Life's too precious.