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  2. Hearing range - Wikipedia

    en.wikipedia.org/wiki/Hearing_range

    The commonly stated range of human hearing is 20 to 20,000 Hz. [6] [7] [note 1] Under ideal laboratory conditions, humans can hear sound as low as 12 Hz [8] and as high as 28 kHz, though the threshold increases sharply at 15 kHz in adults, corresponding to the last auditory channel of the cochlea. [9]

  3. Decibel - Wikipedia

    en.wikipedia.org/wiki/Decibel

    The decibel originates from methods used to quantify signal loss in telegraph and telephone circuits. Until the mid-1920s, the unit for loss was miles of standard cable (MSC). 1 MSC corresponded to the loss of power over one mile (approximately 1.6 km) of standard telephone cable at a frequency of 5000 radians per second (795.8 Hz), and matched closely the smallest attenuation detectable to a ...

  4. Orders of magnitude (frequency) - Wikipedia

    en.wikipedia.org/wiki/Orders_of_magnitude...

    His vocal cords vibrate 1 time every 5.29 seconds. 10 0: 1 hertz (Hz) 1 to 1.66 Hz: Approximate frequency of an adult human's resting heart beat: 1 Hz: 60 bpm, common tempo in music 2 Hz: 120 bpm, common tempo in music ~7.83 Hz: Fundamental frequency of the Schumann resonances: 10 1: 10 hertz 10 Hz

  5. Phon - Wikipedia

    en.wikipedia.org/wiki/Phon

    A sound with a loudness of 1 sone is judged equally loud as a 1 kHz tone with a sound pressure level of 40 decibels above 20 micropascals. [1] The phon is psychophysically matched to a reference frequency of 1 kHz. [2] In other words, the phon matches the sound pressure level in decibels of a similarly perceived 1 kHz pure tone. [3]

  6. Voice frequency - Wikipedia

    en.wikipedia.org/wiki/Voice_frequency

    In telephony, the usable voice frequency band ranges from approximately 300 to 3400 Hz. [2] It is for this reason that the ultra low frequency band of the electromagnetic spectrum between 300 and 3000 Hz is also referred to as voice frequency, being the electromagnetic energy that represents acoustic energy at baseband.

  7. Dynamic range - Wikipedia

    en.wikipedia.org/wiki/Dynamic_range

    Ampex tape recorders in the 1950s achieved 60 dB in practical usage, [26] In the 1960s, improvements in tape formulation processes resulted in 7 dB greater range, [28]: 158 and Ray Dolby developed the Dolby A-Type noise reduction system that increased low- and mid-frequency dynamic range on magnetic tape by 10 dB, and high-frequency by 15 dB ...

  8. Fire alarm notification appliance - Wikipedia

    en.wikipedia.org/wiki/Fire_alarm_notification...

    95 dB @ 3,100 Hz tone are used in many current notification devices. [1] 80 dB @ 520 Hz tone are used in newer notification devices. [1] 70 dB to 100 dB weighted for human hearing (higher decibels, in the 100 to 115 dB range, were common with older electromechanical horns) [citation needed] Light (visible signals) 15 cd to 1,000 cd candela ...

  9. Absolute threshold of hearing - Wikipedia

    en.wikipedia.org/wiki/Absolute_threshold_of_hearing

    [1] The threshold of hearing is generally reported in reference to the RMS sound pressure of 20 micropascals, i.e. 0 dB SPL, corresponding to a sound intensity of 0.98 pW/m 2 at 1 atmosphere and 25 °C. [3] It is approximately the quietest sound a young human with undamaged hearing can detect at 1 kHz. [4]