Silent CD (& MP3s)
What is this?
A CD of silence. (Strictly not a CD of silence, of course, but
audio files
of silence which one can burn to a CD-R to make a CD of silence.)
The tracks are of 2, 4, 8, 16 & 32 seconds and 1, 2,
4, 8, 16 & 32
minutes duration so they can be combined using the play list feature of
a
normal compact disk player to give any duration (in even numbers of
seconds)
from 2 s to an hour (well, up to 1 h 4 min 2 s, to be pedantic).
Uses
- Novelty item: This is the
main reason I made it. Surreal,
silly or stupid depending on your sense of humour.
- Inserting blanks: Sometimes
one wants gaps between tracks
(for example so that one can run between a CD player & a dance
floor when
one is both dance teacher & DJ, as I have been at times, using
an audio
system without a remote control) and to have a track break marker
between the
gap and music track (so that one can skip the blank if needed). To do
that,
just insert one of these silent tracks between each music track before
recording.
- Shutting up an irritating jukebox:
If one wants peace
& quiet but someone else keeps playing CDs on a jukebox or a CD
player to
which you have access, replace their CD with this one. It can similarly
be used
to shut up some irritating mobile telephones by converting a silent
track to an
MP3 and installing it as the ringtone.
- CD player noise test: It can
be used to test a CD player,
amplifier & speakers for background noise. As there is no sound
on the
recording, any noise one hears from the system when playing this is
noise added
by the playing equipment.
- Practical joke: I had not
intended it as a practical joke
but found that one of my friends to whom I gave a silent CD tried
playing it in
a PC and assumed that the computer was failing when it gave no sound
out
(despite the CD being clearly labelled 'Silences'). He was going to
waste time
in a futile attempt to debug his music playing software.
- To silence a CD player when using it as an
amplifier: If
one needs to use a CD player as a amplifier for an auxiliary input,
such as
from an MP3 player, but the amplifier only works with a CD playing then
this
can be used as a dummy CD to keep the CD player happy without producing
unwanted sounds. (This use was invented by a reader of this site, Kane
Zhu, who
used it to fit an MP3 player to a car stereo system in addition to a CD
player
when the stereo's only external input was a dedicated CD player one.)
- To silence a smart phone when using it to output sound from apps:
Several years later another reader similarly found that an iPhone would
only push sound from a satnav application to a car hands-free speaker system when it was playing music and
hence used a silent track as the music.
- To see music
player program animations uninfluenced by
music:
Some music playing computer programs display decorative animations that
adapt to the music. To see what they look like when active but
free-running without music to control them, play a silent track. Some
can look very different to their normal appearance and may even be more
aesthetically pleasing.
- To skip music
player first track:
A reader of this site reported a music player with a bug in its random
shuffle - it only shuffled after it started playing so the first track
was always the same. The solution was to put a short silent track at
the start of the playlist to sacrificially take up that unwanted slot
virtually unnoticeably. (The reader left no return address so I can't
credit them here.)
- As a random timer: The same
reader used a random playlist of silent tracks plus an alarm track as a
substitute for a lost random timer of a board game.
CD Limitations
If you burn the tracks to a audio CD formatted to play in a
normal old
audio CD player then there are 2 restrictions imposed by the original
CD spec:
- All tracks must be >=2 s long. Therefore the 1 s
second track must be
omitted. (I've included it in the download for completeness anyway
though.)
- Although one need not have gaps between the tracks on a
CD, it does
require a 2 s gap before the first track. This will add about 2 s to
the total
timing of silence when playing in a conventional CD player (but the
spin-up
time adds to that as well).
Additionally I have come across (just) one CD player that
mistakenly
reported that the whole CD was of zero length. Maybe it tried to
automatically
skip the silences!
CD Burning Advice
- Set the gap between tracks to zero seconds.
- Use 'Disk at once' mode rather than 'Track at once' mode
(the former is
probably the default anyway on simple to use CD writing programs
anyway) as the
latter does not support gaps between tracks of zero length.
- Turn off any automatic volume equalising/maximising
feature. I don't know
what will happen if your particular CD writing program tries to
normalise a
zero volume recording to maximum (zero divided by zero is
mathematically
indeterminate). It should spot the impossibility & so either
skip the
normalisation or complain. However it might produce noise, might give a
constant DC offset (poor speakers!) or might crash if badly programmed.
- Burn to CD-R not CD-RW as some audio CD players
(particular those made
before CD-RW was invented, of course) cannot read CD-RW. CD-RW uses
dyes that
change colour reversibly whereas CD-R uses irreversibly burnt holes
which are
much more like the original CD stamped holes.
If using the ready-made image rather than individual WAVs,
then only the CD-R not CD-RW is
relevant as I have already done the rest in making the image.
Compressing Nothing
Silence losslessly compresses very well. However the common
file
compression algorithms are not designed for pathological cases like
this (six
hundred million identical zero bytes!) so it needed two passes. The
original
646 MiB of WAV files compressed a thousand-fold to a 640 kiB
.tar.gz
file.
Compressing this again reduced it to a minuscule (by CD standards)
3.55 kiB .tar.gz.gz file. This is an
astounding 186 000
to 1 compression
ratio
overall.
Indeed it compresses better by lossless Gzip or PKzip than
by lossy MP3.
At the lowest quality MP3 encoding that Apple iTunes player offers (16
kibit/s mono) , it
came
to 3.7 MiB, over a thousand times what lossless compression
can do.
However as some audio players have difficulty handling lossless audio
& some users might not want to bother uncompressing the whole
CD if
they only need one track, I've included the shorter MP3s here as
downloads too.
Even better, the 663 MiB CD image compressed down to
2.36 kiB, a 280 000
to 1 compression
ratio.
It is not often that one can download an hour long CD over a
56 kibit/s
modem in under half a second!
Warning
In trying to hear sound from this CD, one is likely to turn
the volume up
high. Remember to turn it back down to a sensible level before later
playing a
normal CD.
Copyright Issue
I think it is okay for me to give away this silence for free
(released
under Gnu Public Licence). There has been one notorious case of the
estate of
J. Cage suing M. Batt for selling a silent recording, Cage having been
an avant
garde composer who had previously published a famous silent piece.
However it
was reported that the suing was because Batt had jokingly credited Cage
with
joint composership of the track without asking permission first
& profited
from the publicity of that creditation without paying royalties. The
suing was
not merely because it was silent as the general concept of silences in
performances & broadcasts pre-dates both Cage & Batt.
Furthermore, both Cage's & Batt's silences were both
based on the
specific novelty of being 'performed' on classical musical instruments
whereas
the silences downloadable here are purely computer generated (in
Syntrillium
Cool Edit) loads of zeros.
My actual inspiration for a joke silent recording came from
David Nobb's
'The Return of Reginald Perrin' in 1977. In that humorous story, a
fictional
company included in its deliberately useless product range silent vinyl
records
with titles such as 'Trappist Monastery Chants' & 'Laryngitis
from Many
Lands'. It was twenty six years before I got around to making one!
Download
Download silent tracks:
- All 12 individual tracks
(1 s, 2 s,
4 s, 8 s, 16 s, 32 s,
1 min,
2 min, 4 min, 8 min, 16 min
& 32 min) in WAV format:
- With Gzip lossless compression for Linux: Silence.tar.gz.gz
(just 4 kiB for an hour!).
- With PKzip lossless compression for M$ Windows: Silence.zip.zip
(just 4 kiB for an hour!).
- Ready-made audio CD image format (suitable for burning from ImgBurn, K3b, Brasero or similar):
- Table of contents for CD case inlay:
- Individual tracks under a minute long in MP3 format: