reply to post by paisley101
I have heard this sound MANY, MANY TIMES as a video professional doing
over 1500 hours of audio & video recording of seminars, tradeshows, video
depositions, interviews, sales meetings, etc. and especially on audio & video
setups in rooms full of hundreds of lawyers, doctors or other professionals
gathered within small rooms, big rooms or anywhere groups of people gather
who have access to certain communications devices which I will outline
Our company has done extensive tracking on the source of this clicking
sound and we do have NUMEROUS digital recordings of that same sound
and of other similar types of pulsed audio on DVD. They ALL have ONE thing
RIM Blackberry, Handspring TREO, and ANY OTHER type of messaging or
mobile phone system that uses packet-based MESSAGING communications
in the 800/900 MHZ or 1800/1900 MHZ spectrum or those that use DataTac
networks. Those clicks are the square wave or sharp-edged pulses
that comprise a portion of the incoming/outgoing email or SMS messages
which have been inducted into a radio antennae or electrically inducted into
the long cables of a microphone or set of headphones.
These pulses are NOT part of the voice-to-voice call portion of cell-phone
service! They ONLY occur on the EMAIL or SMS/TEXT MESSAGING portion
of the cell-phone system.
The phenomenon is highly dependent upon the location, size,
configuration and material that is located within a room that contains
persons who send or receive messages via RIM Blackberries or
Handspring TREO 600 or 650 series mobile device messages or other devices
whose output/input signal consists of a series of square waves or other
sharp-edged pulsed waves that are used as part of a text messaging-based
mobile communications system.
Since these groups of pulses tend to be of short duration between
5 to 15 seconds in length and of limited numbers, I can assume that these
are data packet identifiers used to indicate WHICH PHONE is to receive
a message or which phone is sending a message. It could also be a message
acknowledgement packet indicating that a message has been sent/received
or is awaiting user interaction.
We suggest you obtain a visual-based spectrum analyzer that works
in the 800/900 MHZ and 1800/1900 spectrum or on Datatac Networks
(i.e. RIM Blackberry) and you can visually see the pulses on an
oscilliscope when messages are outgoing and incoming.
The pulses can be attenuated or accentuated enough by a particular room
configuration that they will electrically induct themselves into antennae,
microphone cables or headphone cables or into other microphone-level
recording inputs and thus into your radio output or in our case, the audio
portion of a video recording.
This is also affected by the orientation and length of ANY antennae or cable
which can "grab" the pulses out of the air and that orientation and/or cable
length will determine the strength and clarity of the clicking you hear.
This is not a new phenomenon and unfortunately is only getting worse
as more and more people use these text messaging networks anywhere and everywhere.
I have had to ask whole audiences to PLEASE SHUT OFF THEIR
Blackberries/Treos but as usual, not everyone listens and I therefore
have to explain to an annoyed event organizer that those clicks on my
DVD recordings were caused by errant professionals who just can't keep
themselves away from the digital office for even a few hours!
I hope this explanation helps and do feel free to email me
with any other questions you may have regarding this.
Henry A. Eckstein, Dip. SAIT CTSR (1993)
Audio & Video Production Specialist
Triad Communications Ltd.
Vancouver, British Columbia, Canada