Sleep Sound Generator

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Sleep sounds are continuous audio textures that soften distractions so your mind can settle more easily and drift without the jolt of sudden silence. Many people look for colored noise for sleep and focus because steady sound helps mask conversation, traffic, and small household creaks. You can choose a color profile or a natural ambience and then let it run at a comfortable level that suits your room.

You pick a sound family and set loudness, stereo balance, and a timer so it fades gently at the end rather than cutting off. The finish time shows in your local clock so planning is simple. If you want a bit of movement, a gentle modulation can add natural sway without drawing attention.

A practical example is pink noise at a modest thirty five percent with a twenty minute timer that eases you into the night. Add a small mid boost to bring warmth if your earbuds feel thin. The same approach can help with reading or deep work when nearby chatter would otherwise pull focus.

Keep levels comfortable and give your ears breaks, especially with headphones. Results vary with speakers, walls, and background conditions, so try a few runs and stick with what feels calm and consistent.

Technical Details:

The generator synthesizes a wide‑band random signal and then shapes its spectrum to create classic colored noise families and nature‑like ambiences. Energy balance is adjusted using low and high shelving filters to tilt bass and treble, while a main shape filter (low‑pass, band‑pass, or high‑pass) sets the broad character.

A Low Frequency Oscillator (LFO) can modulate the shape filter’s center or cutoff to add slow, natural movement. User controls cover LFO rate in hertz and depth as a percentage of the base frequency. Stereophonic placement is managed with a pan control, and output loudness follows a perceptual taper so small changes near quiet levels feel smooth.

The live spectrum display shows level in decibels relative to full scale (dBFS) across frequency in hertz (Hz). A smoothing factor controls temporal averaging for a steadier trace. The display helps match profiles by ear and sight, but comfort and masking are the priorities.

G_{out} = {(\frac{V}{100})}^{2}

Symbols and units
Symbol	Meaning	Unit/Datatype	Source
V	Volume setting (percent)	%	Input
G_out	Output gain (perceptual taper)	linear	Derived
f₀	Base shape frequency	Hz	Profile
r	LFO rate	Hz	Input
d%	LFO depth (percent of f₀)	%	Input
d_Hz	LFO depth (absolute)	Hz	Derived
Q	Shape filter quality factor	dimensionless	Profile
pan	Stereo balance	−1 … +1	Input
T_sleep	Sleep timer	minutes	Input
T_fi, T_fo	Fade‑in, fade‑out durations	seconds	Input

d_{Hz} = \min (0.9 \cdot f_{0}, \frac{d}{100} \cdot f_{0})

Worked example. With V = 35 %, G_out = (0.35)² = 0.1225. For a pink profile f₀ = 18 000 Hz and d% = 10 %, d_Hz = min(0.9·18 000, 0.10·18 000) = 1 800 Hz. The color tilt for pink applies approximately +3 dB low and −3 dB high for warmth.

Validation & bounds extracted from code

Inputs, types, and limits
Field	Type	Min	Max	Step/Pattern	Error Text	Placeholder
Sound type	select	—	—	pink, white, brown, blue, violet, ocean, rain, fan, fire, forest	—	—
Volume	range	0	100	step 1	—	—
Pan	range	−1	+1	step 0.01	—	—
Sleep timer	number	0	∞	step 1	—	—
Fade‑in	number	0	∞	step 0.1 s	—	—
Fade‑out	number	0	∞	step 0.1 s	—	—
LFO rate	number	0	∞	step 0.01 Hz	—	—
LFO depth	range	0	100	step 1 %	—	—
Low shelf	number	—	—	step 0.5 dB	—	—
Band freq	number	20	20 000	step 1 Hz	—	—
Band Q	number	0.1	∞	step 0.1	—	—
Band gain	number	—	—	step 0.5 dB	—	—
High shelf	number	—	—	step 0.5 dB	—	—
Spectrum smoothing	range	0	0.99	step 0.01	—	—

Constants & display scale

Constants used by the engine
Constant	Value	Unit	Source	Notes
Color shelf (low / high)	300 / 3 000	Hz	Code	Tilts spectral balance
EQ shelves (low / high)	150 / 6 000	Hz	Code	User tone shaping
Shape filter base Q	0.7–0.9	—	Profile	By preset
Analyzer FFT size	4 096	bins	Code	Frequency data
Spectrum points	192	samples	Code	Log‑spaced
Spectrum x‑axis	20–20 000	Hz	Display	Log scale
Level range	−120–0	dBFS	Display	Typical digital headroom

Units, precision & rounding

Pan shows two decimals; spectrum levels display to one decimal.
Volume converts percent to linear gain using a squared taper.
Numeric inputs enforce step sizes listed above; values clamp to allowed bounds.

I/O formats

Input and output formats
Input	Accepted Families	Output	Encoding/Precision	Rounding
Controls	Sliders & numbers	JSON (settings)	Pretty‑printed	Exact numeric fields
Controls	Sliders & numbers	CSV (table)	Two columns	As displayed

Randomness, seeds & reproducibility

The source signal uses a platform pseudo‑random generator.
Waveform samples are not seeded and are not reproducible across runs.
With identical settings, spectral shape remains consistent even though the raw waveform differs.

Time & calendrics

Timer counts down in minutes using the local clock.
Finish time is shown using your locale’s date and time format.
Fade‑out begins just before the deadline so playback is silent at the scheduled end.

Networking & storage behavior

Audio generation and controls run in the browser; audio is not uploaded.
Copy and download actions use the local clipboard and file save dialogs.
One public asset for the charting layer may be loaded at page start.

Performance & determinism

Real‑time processing updates on the display’s animation frame.
Spectrum reads 4 096‑bin frequency data and reduces to 192 log‑spaced points for plotting.
Identical settings yield the same spectral balance and timing behavior.

Security & hearing safety

No secret keys or untrusted text are processed; inputs are numeric and controlled.
Keep playback at safe levels and avoid extended high loudness, particularly with headphones.

Assumptions & limitations

Noise is synthetic and may sound different across devices and rooms.
Environment and speakers influence masking effectiveness.
Timer uses the device clock; manual clock changes shift the finish time.
LFO depth is capped at 90 % of the base frequency.
Band EQ applies a single peaking filter; complex corrections are out of scope.
Spectrum is indicative; microphone feedback is not used.
Heads‑up Very low or very high EQ boosts can clip downstream stages on other systems.
Heads‑up Headphone leakage and fit affect perceived bass.

Edge cases & error sources

No output until a user gesture starts audio due to autoplay policies.
Extremely low volumes can vanish under system noise gates.
Very long timers may be disrupted by device sleep.
Pan values outside −1…+1 are clamped by the control.
Spectrum smoothing near 0.99 can hide fast changes.
Depth at 100 % with high f₀ still caps at 90 % of f₀.
Band frequencies below 20 Hz or above 20 000 Hz are rejected by validation.
Rapid parameter changes can momentarily desync the display.
Muting system output yields a flat spectrum despite active processing.
Low‑quality speakers may distort when EQ boosts are large.

Privacy & compliance

Processing is browser‑based and client‑only; no audio or settings are transmitted to a server.

How‑to · Step‑by‑Step Guide

Sleep sounds and ambiences are generated, shaped, and faded to a scheduled quiet finish.

Select a sound family (Pink, Ocean, etc.).
Set Volume and optional Pan.
Choose a Sleep timer, then set Fade‑in and Fade‑out.
(Optional) Open Advanced to adjust LFO and EQ.
Press Start, watch the finish time, and settle in.

Caution. Keep levels comfortable to avoid fatigue, especially with headphones.

Example. Pink noise, 35 % volume, 15 min timer, 2 s fade‑in, 3 s fade‑out, band EQ at 1 200 Hz with a gentle +1 dB.

If highs hiss, lower the high shelf or use brown noise.
If the room rumbles, try blue or violet with a small high shelf boost.

When finished, the fade makes silence feel natural and unforced.

FAQ

Is my data stored?

No. Audio and settings remain on your device, and copy or download actions are local only.

Nothing is sent to a server.

How accurate is the spectrum?

It reflects the generator’s output with logarithmic frequency and dBFS levels. Smoothing trades responsiveness for stability and is adjustable.

Use your ears to confirm comfort.

What units are used?

Frequency is in hertz, level in dBFS, time in seconds or minutes, pan is −1 to +1, and EQ gains are in dB.

Rounded for readability.

Can I use it offline?

Audio generation works in the browser. If a chart asset is unavailable, the spectrum tab may not render until it loads again.

Playback is unaffected.

How do I get steady pink noise?

Choose Pink noise, leave LFO depth at 0 %, and keep EQ gains near 0 dB. Adjust volume to taste.

Add a short fade‑in for smooth starts.

What does a “borderline” spectrum mean?

If the trace hugs the top near 0 dBFS, reduce EQ boosts or volume to restore headroom and avoid distortion on other devices.

Aim for comfortable headroom.

Is there a cost or license?

The package does not include licensing terms or payments. It runs as provided.

Check your distribution’s site for policies.

Troubleshooting

No sound: press Start after interacting with the page.
Muted output: check system volume and app volume.
Timer ended early: verify device sleep and clock adjustments.
Harsh highs: reduce high shelf or choose brown noise.
No spectrum: reload when network returns to fetch the chart asset.
Uneven stereo: reset pan to 0.

Blocking issue. If the device does not support the required audio features, playback cannot start. Try a different browser or device.

Advanced Tips

Tip For gentle ambience, set LFO rate to 0.15–0.35 Hz and depth to 5–12 %.

Tip Use a short 1–3 s fade‑in to avoid clicks on some devices.

Tip Notching hiss: set Band to 6–8 kHz with a narrow Q and a few dB cut.

Tip Small volume changes near quiet levels feel bigger; use the taper to fine‑tune.

Tip For reading, try fan or rain with modest highs for clarity.

Tip If the room booms, choose blue or violet to emphasize masking above the rumble.

Glossary

Colored noise: Noise families with different low‑to‑high energy balance.
Pink noise: Warm noise with more low‑mid energy than white.
Brown noise: Deep noise with strong low frequencies.
dBFS: Decibels referenced to full‑scale digital level.
LFO: Low Frequency Oscillator for slow parameter motion.
Q factor: Filter sharpness that controls how narrow a band is.

Sleep Sound Generator

Sleep Sound Generator

Introduction:

Technical Details:

Validation & bounds extracted from code

Constants & display scale

Units, precision & rounding

I/O formats

Randomness, seeds & reproducibility

Time & calendrics

Networking & storage behavior

Performance & determinism

Security & hearing safety

Assumptions & limitations

Edge cases & error sources

Privacy & compliance

How‑to · Step‑by‑Step Guide

FAQ

Troubleshooting

Advanced Tips

Glossary