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Sone

{{Short description|Unit of perceived loudness}}

{{other uses}}

{{redirect|Sones}}

The sone ({{IPAc-en|ˈ|s|oʊ|n}}) is a unit of loudness, the subjective perception of sound pressure. The study of perceived loudness is included in the topic of psychoacoustics and employs methods of psychophysics. Doubling the perceived loudness doubles the sone value. Proposed by Stanley Smith Stevens in 1936, it is not an SI unit.

Definition and conversions

According to Stevens' definition, a loudness of 1 sone is equivalent to 40 phons (a 1 kHz tone at 40 dB SPL).Stanley Smith Stevens: A scale for the measurement of the psychological magnitude: loudness. See: Psychological Review. 43, Nr. 5, APA Journals, 1936, pp. 405–416 The phons scale aligns with dB, not with loudness, so the sone and phon scales are not proportional. Rather, the loudness in sones is, at least very nearly, a power law function of the signal intensity, with an exponent of 0.3.{{cite book

| title = Cochlear hearing loss: physiological, psychological and technical issues | edition = 2nd | author = Brian C. J. Moore | publisher = Wiley-Interscience | year = 2007 | isbn = 978-0-470-51633-1 | pages = 94–95 | url = https://books.google.com/books?id=G6SbxrLVWn4C&pg=PA94 }}{{cite book | title = Physics of The Human Body | author = Irving P. Herman | publisher = Springer | year = 2007 | isbn = 978-3-540-29603-4 | page = 613 | url = https://books.google.com/books?id=vtubxNaSAdAC&pg=PA613 }} With this exponent, each 10 phon increase (or 10 dB at 1 kHz) produces almost exactly a doubling of the loudness in sones.{{cite book | title = Speech and audio processing in adverse environments | author = Eberhard Hänsler, Gerhard Schmidt | publisher = Springer | year = 2008 | isbn = 978-3-540-70601-4 | page = 299 | url = https://books.google.com/books?id=U8cxxaVVjqYC&pg=PA299}}

:

class="wikitable" style="text-align:right"
sone

| 1 || 2 || 4 || 8 || 16 || 32 || 64

phon

| 40 || 50 || 60 || 70 || 80 || 90 || 100

At frequencies other than 1 kHz, the loudness level in phons is calibrated according to the frequency response of human hearing, via a set of equal-loudness contours, and then the loudness level in phons is mapped to loudness in sones via the same power law.

Loudness N in sones (for LN > 40 phon):

{{cite book

| title = Psychoacoustics: facts and models

| edition = 3rd

| author = Hugo Fastl and Eberhard Zwicker

| publisher = Springer

| year = 2007

| isbn = 978-3-540-23159-2

| page = 207

| url = https://books.google.com/books?id=eGcfn9ddRhcC&pg=PA207

}}

:

N = \left(10^{\frac{L_N-40}{10}}\right)^{0.30103} \approx 2^{\frac{L_N-40}{10}}

or loudness level LN in phons (for N > 1 sone):

:

L_N = 40 + 10 \log_{2}(N)

Corrections are needed at lower levels, near the threshold of hearing.

These formulas are for single-frequency sine waves or narrowband signals. For multi-component or broadband signals, a more elaborate loudness model is required, accounting for critical bands.

To be fully precise, a measurement in sones must be specified in terms of the optional suffix G, which means that the loudness value is calculated from frequency groups, and by one of the two suffixes D (for direct field or free field) or R (for room field or diffuse field).

Example values

{{Unreferenced section|date=January 2022}}

:

class="wikitable"

! Description !! Sound pressure !! Sound pressure level !! Loudness

 align="center" | pascalalign="center" | dB re 20 μPaalign="center" | sone
Threshold of painalign="right" | ~ 100align="right" | ~ 134align="right" | ~ 676
Hearing damage during short-term effectalign="right" | ~ 20align="right" | ~ 120align="right" | ~ 256
Jet, 100 m awayalign="right" | 6 ... 200align="right" | 110 ... 140align="right" | 128 ... 1024
Jackhammer, 1 m away / nightclubalign="right" | ~ 2align="right" | ~ 100align="right" | ~ 64
Hearing damage during long-term effectalign="right" | ~ 6×10−1align="right" | ~ 90align="right" | ~ 32
Major road, 10 m awayalign="right" | 2×10−1 ... 6×10−1align="right" | 80 ... 90align="right" | 16 ... 32
Passenger car, 10 m awayalign="right" | 2×10−2 ... 2×10−1align="right" | 60 ... 80align="right" | 4 ... 16
TV set at home level, 1 m awayalign="right" | ~ 2×10−2align="right" | ~ 60align="right" | ~ 4
Normal talking, 1 m awayalign="right" | 2×10−3 ... 2×10−2align="right" | 40 ... 60align="right" | 1 ... 4
Very calm roomalign="right" | 2×10−4 ... 6×10−4align="right" | 20 ... 30align="right" | 0.15 ... 0.4
Rustling leaves, calm breathingalign="right" | ~ 6×10−5align="right" | ~ 10align="right" | ~ 0.02
Auditory threshold at 1 kHzalign="right" | 2×10−5align="right" | 0align="right" | 0

See also

References

{{reflist}}

External links

  • [http://www.sengpielaudio.com/calculatorSonephon.htm Correlation between sones und phons − calculator]

Category:Hearing

Category:Human-based units of measurement

Category:Units of sound