Sound Detector

Discussion in 'The Projects Forum' started by ECErich, Feb 4, 2015.

  1. ECErich

    Thread Starter New Member

    Feb 4, 2015
    5
    0
    Hi Everyone,

    I was trying to build a circuit, i just want to find out how to start my design. Basically the circuit works if the presence of the sound is within the area. Can you help me where to start?

    Thanks,
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,061
    3,826
    get a microphone (electret is easiest)
    Connect to an op Amp.

    OPTION 1
    Connect to an LM3915.
    Connect 3915 to 10 LEDs to show sound level (see data sheet for range of each LED)

    Option 2
    Connect Op Amp ampliefier to volt meter and read sound level


    OPTION 3
    Connect OP Amp as comparator
    Connect Op amp output to simple LED (Sound above threshold yes/no)

    Option 4...

    You need to tell us what "presence of sound" means and what kind of output accuracy you need. What kind of output you need (light, bar graph, number, buzzer, actuator, motor, ...)
     
    LoveElecs and Reloadron like this.
  3. ECErich

    Thread Starter New Member

    Feb 4, 2015
    5
    0
    Thank you GopherT for you reply. The "presence sound" is the sound of the Cane Toad(Frog). I try to simulate it using Audicity Software to get the response between time vs amplitude and freq vs db. I want to determine the operating frequency and design a circuit that can only detects the Cane Toad sound.The output that I'm planning to be use is motor.
     
  4. wayneh

    Expert

    Sep 9, 2010
    12,148
    3,058
    And define what you mean by "sound", in terms of frequency. 12kHz is sound to my kids, but not me.

    Oops, cross post.
     
  5. ECErich

    Thread Starter New Member

    Feb 4, 2015
    5
    0
    The operating frequency by simulation is 720Hz.
     
  6. vikasbly44

    New Member

    Jan 19, 2015
    13
    1
    you can get a microphone.
    OR

    you can Connect Op Amp ampliefier to volt meter and read sound level and freequency.
     
  7. ECErich

    Thread Starter New Member

    Feb 4, 2015
    5
    0
    Thanks to you all,

    I want to create a project that can only detect the sound of a frog that can output to a servo motor. If the sound detected is not a frog voice the circuit does not operate.
     
  8. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,061
    3,826
    If that is the case, you need to tell us what is unique about the sound of the frog that be isolated from other sounds.
     
  9. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,804
    1,105
    :confused: I'm puzzled. Are you training a frog to control a servo?
     
    absf likes this.
  10. Reloadron

    Active Member

    Jan 15, 2015
    963
    232
    Well not so sure as to the frog, I haven't spoken to any lately. However, when I was talking with frogs each did have a unique voice by species of frog.

    If you want something to respond to a narrow band of frequencies you might be able to do it with a notch filter of sorts. Just a matter of knowing the frequency range you want and filtering out frequencies above and below. The trick is knowing the frequency range you want.

    Ron
     
    absf and Sinus23 like this.
  11. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,175
    397
    Does frog croak in a repeating pattern, say 3 croaks in 5 sec? Each croak lasts about 1 sec? Do we need to know direction of sound?
     
  12. absf

    Senior Member

    Dec 29, 2010
    1,493
    372
    Let's wait and hear what MrChips has to say about this...:D

    (just kidding)

    Allen
     
    GopherT and Sinus23 like this.
  13. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,061
    3,826
    I think a filter will work better when coupled with a Microcontroller. Most frogs have a quickly repeating tone. Like a 120 Hz that flutters on/off at about 4 to 8 Hz. Get a sound file and look at it as an oscilloscope view and see what unique identifying features you can find.
     
  14. ECErich

    Thread Starter New Member

    Feb 4, 2015
    5
    0
    I uploaded some spectrum graph. Can you tell me what type of approach and design that I need to do.


    Sorry everyone if i cannot explain it more clearly and specific. That's why I'm here to seek help!. thank you all
     
  15. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,348
    Hello,

    Switch the view for the frequency to log.

    The -15 dB states that the signal is 15 dB weaker as the reference level.
    16 dB is about 40 times.
    See the links of this page for more info on dB's:
    http://educypedia.karadimov.info/electronics/decibels.htm
    As the reference level is not given, you do can not calculate the real level.

    Bertus
     
  16. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,175
    397
    A good start. Are there any other sounds in the neighborhood that are close to the frog? Does the pattern for both repeat in any recogniasible pattern?
     
  17. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,804
    1,105
    Do male and female cane toads have different calls?
     
  18. Magician

    New Member

    Aug 18, 2014
    13
    6
    No , you can't use frequency - magnitude plot only. Timing is very important as well. What you need is frequency-time-magnitude, they called it's waterfall spectrogram.
     
    GopherT likes this.
  19. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,804
    1,105
    The cane toad call waveform looks like this :-
    CaneToad.gif
    Each major burst shown consists of a series of many minor bursts repeated at ~ 16Hz. Here's a series of just three minor bursts :-
    CaneToadx.gif
    Each minor burst consists of an amplitude modulated tone of ~605Hz (though the tone frequency varies slightly within a minor burst). The modulation envelope has strong periodic components at ~77Hz and 105Hz.
    A starting point in identifying a toad call might therefore be to build an amp plus a narrow-band-pass filter centred on 605Hz. But variations in call between gender/species/individuals would probably mean more complex signal processing would be required.

    An MP3 of the toad call is downloadable from here.
     
    Bernard likes this.
Loading...