Search results
Results from the WOW.Com Content Network
Audio therapy is the clinical use of recorded sound, music, or spoken words, or a combination thereof, recorded on a physical medium such as a compact disc (CD), or a digital file, including those formatted as MP3, which patients or participants play on a suitable device, and to which they listen with intent to experience a subsequent beneficial physiological, psychological, or social effect.
Frequencies below 20 Hz are generally felt rather than heard, assuming the amplitude of the vibration is great enough. Sound frequencies above 20 kHz are called ultrasonic. Sound propagates as mechanical vibration waves of pressure and displacement, in air or other substances. [5] In general, frequency components of a sound determine its "color ...
[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] The human auditory system is most sensitive to frequencies between 2,000 and 5,000 Hz. [10]
This does not mean that frequencies above 100 kHz are audible, but that time discrimination is not directly coupled with frequency range. [7] [8] Frequency resolution of the ear is about 3.6 Hz within the octave of 1000–2000 Hz That is, changes in pitch larger than 3.6 Hz can be perceived in a clinical setting. [6]
The frequency of baleen whale sounds can range from 10 Hz to 31 kHz, [27] and that of elephant calls from 15 Hz to 35 Hz. Both can be extremely loud (around 117 dB ), allowing communication for many kilometres, with a possible maximum range of around 10 km (6 mi) for elephants, [ 28 ] and potentially hundreds or thousands of kilometers for some ...
The sound appears to pulsate only when heard through both earphones. Time duration of 10 seconds Binaural Beats Base tone 200 Hz, beat frequency from 7 Hz to 12.9 Hz. Time duration of 9 minutes. "Binaural beats were first discovered by physicist Heinrich Wilhelm Dove in 1839.
The first research on the topic of how the ear hears different frequencies at different levels was conducted by Fletcher and Munson in 1933. Until recently, it was common to see the term Fletcher–Munson used to refer to equal-loudness contours generally, even though a re-determination was carried out by Robinson and Dadson in 1956, which became the basis for an ISO 226 standard.
Very high power levels of 160 dB were achieved at frequencies of 2–3 Hz. Test frequencies ranged from 0.5 Hz to 40 Hz. Test subjects suffered motor ataxia, nausea, visual disturbance, degraded task performance and difficulties in communication. These tests are assumed by researchers to be the nucleus of the current urban myth. [2] [3]