I would like to generate a low frequency signal to use as a sort of white noise to mask something that’s occasionally waking me. I have no control of this other audio, it is produced by neighbors for harassment.
I just suspect it is occasional blasts of low frequency audio. I am not sure of the exact frequency, but assume I can “mask” it in the same way an air conditioner or fan might mask common neighborhood noise.
My idea is just to connect headphones or speakers to my laptops speaker output. And slowly increase the volume. Will most headphones / PC speaker sets be able to handle low frequencies … I am just guessing its ~500 hz.
I also meant to ask, if I were to use audacity to generate the sound, then save it as a WAV or MP3 file, could I the use a PC to continually play that back - and still get the ~500 hz signal ? I mean … is there anything in my scheme that does not handle audio that is at that frequency ???
500 Hz is not very low, it is rather in the lower mid-range.
It would probably be best to first record the annoying sound in order to specify the frequency range and to generate a 1:1 comparison with some comfort noise.
You can alternatively just try different sounds, e.g. Surf LFO (sea waves) or Pink noise with an additional lowpass filter.
There is a Generate option at the top of the Audacity window. You can use it to generate pure tones or 3 different types of noise. Listen to the 3 types of noise to see which one you prefer. After generating the noise, you can optionally use the Equalizer* effect to change the “tone” of the sound.
I am just guessing its ~500 hz.
500Hz is NOT low frequency… 500Hz doesn’t sound like bass. I suggest you experiment with generating different frequencies to get a feel for it. 20Hz is considered the lowest frequency humans can hear. The lowest note on a standard electric bass is a little above 40Hz. (Be careful with loud high-frequency test-tones above around 5kHz, because you can blow a tweeter if you have a high-power amplifier. Woofers can handle more power.)
Will most headphones / PC speaker sets be able to handle low frequencies …
It takes a big woofer/subwoofer and a big amplifier to reproduce strong-deep bass. An “average” pair of headphones can generally reproduce quite a bit of bass. If you generate some test-tones, you can check your speakers/headphones.
then save it as a WAV or MP3 file, could I the use a PC to continually play that back - and still get the ~500 hz signal ? I mean … is there anything in my scheme that does not handle audio that is at that frequency ???
Any soundcard can handle the “traditional” audio range of 20Hz to 20kHz. Speakers, headphones, and amplifier power are the limiting factors.
MP3 should be fine, and you can set up your player software to play continuously in a loop so don’t need a long file.
- After using the Equalizer, it’s a good idea to use the Amplify effect to make sure your peaks don’t go above 0dB. If you save a file that goes over 0dB you can get distortion. Distortion may not be too bad since you are generating noise anyway, but it will change the character of the sound and there is more danger of frying a tweeter.
Not sure all this makes sense. Some have suggested that while things producing white noise (AC units, fans, etc) may be able to “mask” a variety of inner city noises … the very low frequencies have a different impact and it’s no longer an issue of masking them, it’s just their presence is disturbing and the concept of masking them doesn’t really accomplish anything.
I’ve tried a tone of about 200 hz … plays ok via my headphones. I actually use them while i sleep.
Anyone know if i’ll suffer any ill effects by listening to a 200 hz tone all night … assuming its not the volume … will keep that low ?
That’s more of a psychology issue… I’d say it’s worth trying.
Masking does work at low frequencies. Masking should work as long as the masking-noise is louder than the noise you’re trying to block-out, and it works best if the masking noise is approximately the same frequency as the annoying noise. However, you may find the masking noise just as annoying, or more annoying.
It’s generally easier to sleep with a constant noise that you can get used to than sudden-intermittent noise. for example, you may be able to fall asleep with the radio or TV on, but if you are sleeping and somebody turns-on the radio, you’ll probably wake-up.
I’ve used some loud ocean wave sounds, and it’s not so easy to go to sleep with loud wave sounds either. Then I found myself trying to hear the offensive noise through the waves. After awhile (more than one day) I adjusted to it and the waves were preferable to the neighbor’s noise, but not preferable to silence. Quiet waves might be relaxing, but loud storm waves are not as relaxing as silence… At least not to me.