Hi list ! This is the first time I get involved in the Pure Data mailing list, a kind of newbie then and I'm currently facing to a problem for which I have no competences : I've got a buzzer which aims at producing a sound sequence when a certain default occurs. The buzzer behaviour is controlled by two parameters : its volume and the waveform used to produce the alarm sequence. It seems for many people that the alarm level is not enough strong, even at full blast so here's my question : do you know if there are some rules that make a sound appear more strong than another at an identic level ? Does the solution resides in considering a square wave (or whatever else) instead of a sine one ? Or should I have to set up a more complex waveform (such as major chords, add a square to a sine...) ?I know that it doesn't directly concern PD but... Thanks for your help ! touti
Faites un voeu et puis Voila ! www.voila.fr
hi,
I'm not sure I completely understand the question but I'll give it a shot:
I read:
have no competences : I've got a buzzer which aims at producing a sound
what's a buzzer ? like a huge gameshow button ?
sequence when a certain default occurs. The buzzer behaviour is controlled by two parameters : its volume and the waveform used to produce the alarm sequence. It seems for many people that the alarm level is not enough strong, even at full blast so here's my question : do you know if there are some rules that make a sound appear more strong than another at an identic level ?
higher freuqncies are generally perceived as louder
Does the solution resides in considering a square wave (or whatever else) instead of a sine one ? Or should I have to set up a more complex waveform
square waves have rich harmonics = more high frequencies -> they will be per- ceived as louder than a pure sine at the same level.
(such as major chords, add a square to a sine...) ?
this might not work as expected, esp. since you'll require noticeable dynamic changes.
http://www.indiana.edu/~emusic/acoustics/acoustics.htm
HTH
x
As Chris mentioned, different frequecies "appear" to be louder or softer. Our ears are especially designed to tune in to the frequencies of human speech. That's generally why certain music, even when played at high volume, doesn't blot out you talking to your friend at the club, restaurant, whatever. Higher freqs, especially those around 1-2 KHz, seem louder. At higher volumes, these are the some of freqs which also cause the most discomfort!
See here [linked also from the page Chris mentioned]:
http://hyperphysics.phy-astr.gsu.edu/hbase/sound/eqloud.html#c1
Another thing to think about: lower frequencies are less directional that higher ones. It doesn't take a lot of volume if you use a short, high frequency "blast" to call someone's attention to a specific spot in the room. Think about mobile phone ring tones. Or fire alarms.
Last, you might consider using a piezoelectric disc as your speaker. Usually these are resonant at some very attention-getting frequency, and can take less power to drive than a normal loudspeaker at the same pitch. Attaching the disc to another resonant object [big metal box, etc] will certainly amplify the effect.
best, d.
" tboulanger@voila.fr wrote:
Hi list !
This is the first time I get involved in the Pure Data mailing list, a kind of newbie then and I'm currently facing to a problem for which I have no competences : I've got a buzzer which aims at producing a sound sequence when a certain default occurs. The buzzer behaviour is controlled by two parameters : its volume and the waveform used to produce the alarm sequence. It seems for many people that the alarm level is not enough strong, even at full blast so here's my question : do you know if there are some rules that make a sound appear more strong than another at an identic level ? Does the solution resides in considering a square wave (or whatever else) instead of a sine one ? Or should I have to set up a more complex waveform (such as major chords, add a square to a sine...) ?I know that it doesn't directly concern PD but... Thanks for your help !
touti
Faites un voeu et puis Voila ! www.voila.fr
hi
" tboulanger@voila.fr schrieb:
Hi list !
It seems for many people that the alarm level is not enough strong, even at full blast so here's my question : do you know if there are some rules that make a sound appear more strong than another at an identic level ?
the crest-factor decribes the energy of the sound in relation to its amplitude. the waveform with the highest crest-factor is a squarewave (imagine: the positon of the membrane of the loudspeaker is always at maximum position). using a square should result in the maximum loudness at a specific amplitude. our is ear is the most sensitive in the area between 1 to 4kHz (as chris and derek already mentioned).
another approach: what about making the beep-sound of your buzzer pulse? noises without constant amplitudes seem to get more attention.
roman
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" <tboulanger＠voila.fr> -
CK -
derek holzer -
Roman Haefeli