|
August 1962 Electronics World
Table of Contents
Wax nostalgic about and learn from the history of early electronics. See articles
from
Electronics World, published May 1959
- December 1971. All copyrights hereby acknowledged.
|
The August 1962 issue of
Electronics World magazine featured what could be considered as an early
"infographic" on the topic of sound, music, and audio. Frequency and volume, perceived
equal loudness levels, the audible frequency spectrum, musical frequency ranges,
typical age-related hearing loss, relative sound levels in decibels, and the musical
scale are included. The sound power level chart ranges from the threshold of hearing
value of 10-16 watts/cm2 (0 dBA) to standing 80 feet
from the tail of a North American
F-86 Sabre Jet taking off, which is a couple dB above the threshold of pain
at 10-3 watts/cm2 (130 dBA). The charts were useful (and
still are for that matter) to the audiophiles who looked to electronics magazines
of the era for technical information. BTW, the loudest possible sound pressure level
is around 191 dBA, whereafter it is into the
shock wave realm of sound
pressures.
Sound | Audio | Music Infographic
Frequency & Volume Ranges
The approximate boundaries of normal hearing based on Fletcher-Munson data. No
sound is heard below the level indicated by the lower contour. Sound levels that
are in excess of those indicated by the upper contour are felt rather than heard
and may be accompanied by a sensation of pain. Also shown are the volume levels
and frequency ranges of music as well as speech.
Equal Loudness Curves
Sound intensities required to produce equal loudness at various sound levels.
These curves, obtained by
Robinson and Dadson,
are slightly different from the older
Fletcher-Munson
data and have as yet to be internationally accepted. Both these curves and the Fletcher-Munson
curves of equal loudness show the need to boost the bass substantially and to boost
the treble slightly when listening at reduced volume levels. If this is not done,
then bass and treble tones will appear to be lost.
Audible Spectrum
Some significant frequencies are shown on the audible spectrum along with the
fundamental frequencies for notes on the piano keyboard. The equally tempered scale
is used and it is based on the American Standard Pitch (A=440).
Musical Frequency Ranges
Fundamental frequency ranges of voices and musical instruments. Note that the
range of the overtones, which give an instrument its particular timbre, is not shown.
Although these vary widely depending on the instrument and how it is played, the
overtones may extend the frequency range required to re-produce a given musical
instrument by two or more octaves.
Hearing Loss with Age
Curves show the loss of hearing acuity with advancing age. Note that high-frequency
hearing loss of women is considerably less than for men.
Sound Levels
The relative levels of a number of common sounds and noises.
Posted May 18, 2021
