Sound Level Converter

Our Sound Level Converter is a comprehensive tool that helps you convert between different units of sound measurement: decibels (dB), phon, and sone. Whether you’re working on acoustics, audio engineering, or noise control projects, this calculator makes sound level conversion simple and accurate.

Understanding Sound Measurement Units

Primary Unit

Decibel (dB)

The decibel is a logarithmic unit used to express the ratio between two values of a physical quantity. In acoustics, it typically represents sound pressure level (SPL) relative to the threshold of human hearing (20 micropascals).

Psychoacoustic Units

Phon

The phon is a unit of perceived loudness level, equal to the decibel level of an equally loud 1 kHz tone. A sound of N phons has the same perceived loudness as a 1 kHz tone at N decibels SPL.

Sone

The sone is a linear unit of perceived loudness. One sone is defined as the loudness of a 40-phon (1 kHz) tone. Unlike phons and decibels, sones are linear – doubling the sone value represents a doubling of perceived loudness.

Conversion Relationships

Here are the key relationships between different sound measurement units:

Decibel to Other Units

• At 1 kHz, dB SPL equals phons
• Sone conversion uses a logarithmic relationship

Phon to Other Units

• At 1 kHz, phons equal dB SPL
• 40 phons = 1 sone
• Each 10-phon increase doubles the sone value

Sone to Other Units

• 1 sone = 40 phons
• Phon = 40 + (10 × log₂(sone))
• dB conversion depends on frequency

Common Sound Level References

Here are some common sound level measurements:

• Threshold of hearing: 0 dB (0 phons, 0 sones)
• Whisper: 30 dB (~30 phons, ~0.15 sones)
• Normal conversation: 60 dB (~60 phons, ~4 sones)
• City traffic: 80 dB (~80 phons, ~16 sones)
• Rock concert: 110 dB (~110 phons, ~256 sones)
• Pain threshold: 130 dB (~130 phons, ~1024 sones)

How to Use the Calculator

1. Enter a value in any of the input fields
2. The calculator will automatically convert and display the equivalent values in other units
3. Use the Reset button to clear all fields and start a new conversion
4. Hover over the input fields for helpful tooltips

Applications

Sound level conversion is essential in many fields:

• Acoustics: Analyzing sound properties and behavior
• Audio Engineering: Mixing and mastering audio
• Noise Control: Assessing and mitigating noise pollution
• Industrial Safety: Monitoring workplace noise levels
• Product Design: Meeting noise emission standards
• Environmental Studies: Measuring environmental noise

Tips for Accurate Conversion

1. Always double-check critical measurements
2. Use decimal points for precise measurements
3. Consider rounding to appropriate precision for your application
4. Be aware of significant figures in your measurements

Technical Notes

This calculator provides conversions accurate to one decimal place, which is sufficient for most practical purposes. For extremely precise measurements or scientific applications, please use specialized measuring equipment and conversion tools.

Important considerations for sound level measurements:

• Frequency dependence of human hearing
• Reference sound pressure level (20 µPa)
• Measurement weighting (A, B, C, or Z)
• Temporal characteristics (fast, slow, impulse)
• Environmental conditions

Note that these conversions assume:

1. Standard atmospheric conditions
2. Free-field measurements
3. 1 kHz reference frequency
4. A-weighting for decibel measurements
5. Standard observer response curves