Method Of Sonic Conditioning

Abstract

A method of sonic conditioning an area comprising the step of radiating in said area a cyclic sonic pattern having random variations of predetermined limits of amplitude in the audible frequency range, said limits of amplitude falling within a range of approximately 85 to 100 percent of the maximum amplitude for said sound pattern (and preferably within a range of approximately 88 or 90 to 100 percent of said maximum amplitude), said cyclic sound pattern having a sound pressure level sufficient to mask environmental sounds within said area. This method of sound conditioning may also include an additional step of transmitting to or radiating in said area from a second location a second cyclic sonic pattern as aforedescribed. This method of sound conditioning in an area may also include the step of transmitting to said area at a predetermined time interval or delay a second identical cyclic sound pattern either from the same or a different location. The frequency variation for the cyclic sound pattern contemplated by this invention falls within a range between approximately 30 cycles per second to 10,000 cycles per second.

Description

BACKGROUND OF THE INVENTION

Heretofore, many attempts have been made to sound condition areas, rooms or the like. Illustrative of these attempts is the use of music to effect such sound conditioning. However, experience has shown that while a certain type of music may be pleasing to some of the listeners, it may be annoying or disturbing to other listeners. Additionally, even though certain types of music may be initially pleasing to some listeners, it has been found that after a period of time the identical type of music may become annoying or disturbing to such listeners. Thus, all previous attempts of sound conditioning areas, rooms or the like have suffered from the inability to find a method which would produce a pleasing, nonannoying sound pattern for all listeners for extended periods of time. In addition, the many previous attempts to sound condition an area, room or the like have fallen short of the goal since such attempts involved not only the wrong type of sound pattern, but also such sound patterns emanated from a single source which resulted in the listener becoming space oriented to the location of the single source of sound.

SUMMARY OF THE INVENTION

It has been found that the foregoing disadvantages may be easily overcome through the use of a method of sound conditioning an area comprising the step of transmitting to said area a cyclic sound pattern having random variations of predetermined limits of amplitude in the audible frequency range, said limits of amplitude falling within a range of approximately 85 to 100 percent of the maximum amplitude for said pattern, said cyclic sound pattern having a sound pressure level sufficient to mask environmental sound. Space diversity or spatial effect may be simulated or achieved by transmitting a second cyclic sound pattern either similar to or identical with the first cyclic sound pattern either from a different location or from the same location but at a different time interval as compared with the first cyclic sound pattern.

Accordingly, one of the principal objects of this invention is to provide a new and improved method of sound conditioning an area.

Another object of this invention is to provide a method of sound conditioning which reduces or substantially eliminates the annoyance heretofore experienced from various environmental sound.

Another object of this invention is to provide a method of sound conditioning an area, room or the like through the use of a random varying but cyclic repetitious sound pattern.

Another object of this invention is to provide a novel method of sound conditioning comprising the step of transmitting into said area cyclic sound pattern having random variations of amplitude and frequency, said variations falling within the range of approximately 85, 88 or 90 to 100 percent of the maximum amplitude for said sound pattern and said frequency variations falling within a range between approximately 30 cycles per second and 10,000 cycles per second said cyclic sound pattern having a sound pressure level sufficient to mask environmental sound.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing objects and other advantages of the invention will become apparent from the following description and claims and the accompanying drawings wherein:

FIG. 1 is a block diagram view of an apparatus used in practicing the method of this invention;

FIG. 2 is a representation of the cyclic sound wave form as displayed on a cathode ray oscilloscope screen;

FIG. 3 is a representation of a cyclic sound wave form as displayed on a different type of cathode ray oscilloscope screen;

FIG. 4 is an enlarged view of a portion of the cyclic sound wave form shown in FIG. 3 and contained within the encircled portion designated with the numeral 4;

FIG. 5 is an enlarged view of a portion of the cyclic sound wave form shown in FIG. 3 contained within the encircled portion designated with the numeral 5; and

FIG. 6 is an isometric view of a portion of the apparatus shown in FIG. 1.

DESCRIPTION OF THE EMBODIMENTS

As previously indicated, the primary object of this invention is to provide a system of sound conditioning compatible with several basic functions of the human system. It has been found that the ear is more sensitive in a quiet environment or background and becomes less and less sensitive to the sound as the background increases in loudness. In other words, the ear can be desensitized by natural function and thereby made less acceptable to unwanted sound. It has also been noted that ordinary individual reaction to different sounds is related to the quality of the sound. For example, it is known that certain sounds are annoying and therefore would be unwanted or avoided. These sounds include an impulse-type sound such as occurs with a jack-hammer operation, a throbbing, fluttering sound such as encountered with a continuous supply of air flowing through a grille or a duct, and a high-pitched, shrill, or warbled sound such as a siren, whistle, or the screech of an animal. The method of this invention would not generate these types of sounds but would effectively mask any of these sounds which might be encountered.

Referring now to the drawings, in FIG. 1 is shown a block diagram with an apparatus useful in effecting the method of this invention. The apparatus shown in FIG. 1 comprises a generator 12, an amplifier 14, and a transducer 16. The generator 12 is used to produce an electrical voltage having amplitude variations within a frequency range which is audible to the normal ear and preferably within a frequency range of approximately 30 cycles per second up to approximately 10,000 cycles per second. The variation of the voltage amplitude of one wave form to another is limited to a fraction of the maximum amplitude in the order of magnitude of 10 to 15 percent. The electrical voltage or signal produced by the generator 12 passes through the amplifier 14 and is radiated or transmitted from transducer 16. The transducer 16, in its most common form, includes a loudspeaker which, if desired, could be replaced with an earphone.

The electrical voltage or signal produced by the generator 12 has a special characteristic. First of all, this signal does not include any sharply pulsating or predominately piercing characteristics. Rather, it is cyclic in nature and has random variations of amplitude and frequency. The amplitude variation falls within the range of approximately 85 to 100 percent of the maximum amplitude while the frequency variation falls between a range of approximately 30 cycles per second and 10,000 cycles per second. A better understanding of this type of signal is had from examining FIGS. 2--5. In FIG. 2 is shown the voltage wave form as same is displayed on a cathode ray oscilloscope screen in an instrument capable of displaying voltage amplitude on the vertical axis and frequency response on the horizontal axis. In FIG. 2, the circle designated by the numeral 18 represents the face of an oscilloscope which has a zero voltage reference line 20 and a varying voltage wave form having maximum peaks at line 22 and minimum variations at line 24. The horizontal scale represented by the numeral 26 shows the frequency in thousand of cycles per second in which the voltage variations are occurring.

As previously indicated, the limitation of voltage variations between lines 22 and 24 would be approximately 10 percent of the total voltage between the zero voltage reference line 20 and the maximum peak line 22. It is to be understood that good results are obtained where the voltage varies between approximately 10 and 12 percent of the total voltage between lines 20 and 22 as well as 10 to 15 percent. It will be noted that the wave form varies randomly within the range of approximately 30 cycles per second and 10,000 cycles per second.

In FIG. 3 is shown the face 28 of yet another oscilloscope. In FIG. 3, the zero voltage reference line is designated with a numeral 30. The face 28 of the oscilloscope displays a varying voltage wave form 32 and a time scale 34 which is represented in fractions of a second. The full extent of the time scale 34 as shown in FIG. 3 represents approximately 2 seconds. At each of the ends of the wave form 32 are encircled areas designated with the numerals 4 and 5, respectively. That portion of the wave form included in circle 4 is shown in enlarged detail in FIG. 4. That portion of the wave form shown in circle 5 is shown in enlarged form in FIG. 5. In FIG. 4, the starting point of the wave form 32 is designated by the numeral 36 while in FIG. 5 the end of the wave form is designated by the numeral 38. In FIG. 5 the continuation of the wave form 32 is shown in broken lines and designated by the numeral 32'. In essence, the wave line form 32' is identical to the wave line form 32. Thus, it will now be understood how the randomly varying wave form 32 which ends at point 38 as shown in FIG. 5 can continue through another cycle as illustrated by the wave line form 32' as shown in FIG. 5.

In FIG. 6 is shown one embodiment of a generator which can be used in the apparatus shown in FIG. 1. The generator shown in FIG. 6 includes s disc 40 which may be made from a number of materials such as nonferric metal, plastic or ceramic, on which is bonded a layer 42 of especially selected iron-based particles such as iron oxide. The magnetic field pattern 44 is formed upon this layer 42. At least one of the pulleys 46 and 48 is externally driven and, thus, causes the disc 40 to rotate at a constant speed. The magnetic sensor or pickup 50 senses the magnetic field pattern 44 formed on the layer 42 and generates an electrical voltage or signal which is proportional to the magnetic field 44. The signal generated by the magnetic sensor 50 is transmitted, such as by wires 52, to an amplifier and then to a reproducing transducer, such as the amplifier 14 and transducer 16 shown in FIG. 1. The point designated by the numeral 54 on the magnetic field pattern 44 corresponds to point 36 as shown in FIG. 4 and to point 38 as shown in FIG. 5. In other words, the point 54 as shown on disc 40 represents both the beginning and the end of a magnetic field pattern 44.

Although it will be appreciated that the disc diameter and turning rate may vary over a large range, it has been found that excellent results were obtained with a disc approximately 2 inches in diameter and rotating at a speed of approximately 90 revolutions per minute. It will also be appreciated that the disc 40 shown in FIG. 6 may be formed from a transparent material and the coating 42 may comprise a photographic emulsion or an embossed pattern each of which contains information equivalent to pattern 44. A photoelectric type cell working with an associated light source and lens system or stylus-type transducer may be used in lieu of the magnetic pickup 50. It will also be appreciated that multitrack generators using magnetic photographic, or embossed tracks can involve the use of cylinders as well as discs. As previously indicated, it is often desirable to create space diversity or produce a spatial effect. Sometimes this is referred to as stereophonic sound. This may be accomplished through the use of more than one generator system having a single track or by a system using a generator with more than one track as well as more than one amplifier and transducer. With regard to space diversity, it has been found that a single source of sound in a room causes a person to become space-oriented to the location of the single source. Such a person may become annoyed if he can point to the location without ever seeing the source. However, if two or more random type sound sources, i.e., sound sources which do not noticeably differ from each other in overall character, originate at different locations in an area or room to be sound conditioned, space diversity will make it difficult if not impossible to detect a specific location of the sound source. A simulated space diversity is achieved with the use of a duplicate second sound track which is located at a different radial position on the disc 40, i.e., one of the sound tracks is shifted slightly in relative time. When the sound from these two tracks is transmitted, it has been found that a fixed spatial difference between the two sounds occurs which causes a third dimensional realism somewhat similar to that produced by stereophonic recordings.

It will be appreciated that there are a number of ways of producing sound patterns contemplated for use in the method of this invention. For example, a high frequency carrier wave could be modulated at small amplitude and then demodulated thereby creating a controlled, small variation of a sound wave.

In view of the foregoing, it can be readily appreciated that a new and improved method of sound conditioning an area has been described. The method of this invention is accomplished with a compact, inexpensive and simple-to-operate apparatus. Such an apparatus may be carried by salesmen, business men or other travelers, and used in motels and hotels at night. Additionally, such an apparatus can be used very beneficially by sick persons, particularly those who are confined in hospitals. Further, the method of this invention has been found to be pleasing to all individuals, and such individuals do not, even after prolonged exposure, become annoyed or disturbed by this method of sound conditioning. Also the discs are small in size, inexpensive to manufacture and easily changed. Thus, a new disc may be quickly and easily inserted in an appropriate generator when the quality or nature of the sound of the old disc becomes unsuitable.

It is to be understood that this invention is not limited to the exact method described, which is merely by way of illustration and not limitation, as various other forms and modifications will be apparent to those skilled in the art; and it is therefore intended that the appended claims cover all such changes and modifications.

Claims

I claim:

1. A method of sound conditioning a predetermined area to mask environmental sound comprising the steps of:

producing a cycle of sound primarily in the audible frequency range that is soothing to the human ear, the pattern of sound within said cycle having random variations in frequency with respect to both time and amplitude and random variations in amplitude, said random variations in amplitude varying over a range lying between 85 and 100 percent of the peak amplitude of the sound in said pattern;

successively and continuously repeating said cycle to produce a continuous, repetitive, pattern of sound;

radiating said continuous, repetitive, pattern of sound in said predetermined area; and,

maintaining said continuous, repetitive, pattern of sound at a sound pressure level sufficient to mask environmental sound.

2. A method as claimed in claim 1; and, in addition, producing and radiating s similar continuous, repetitive, pattern of sound from a different location in said predetermined area to produce a sound mixture which confuses identification of source.

3. A method as claimed in claim 1; the duration of the cycle being not in excess of a few seconds.

4. A method as claimed in claim 1; the duration of the cycle being less than 1 second.

5. A method as claimed in claim 1; the frequency variation falling within a range between approximately 30 cycles per second and 10,000 cycles per second.

6. A method of sound conditioning a predetermined area to mask environmental sound comprising the steps of:

producing a cycle of sound primarily within the audible frequency range that is soothing to the human ear, the pattern of sound within said cycle having random variations in frequency with respect to both time and amplitude and random variations in amplitude;

successively and continuously repeating said cycle to produce a continuous, repetitive, pattern of sound;

radiating said continuous, repetitive, pattern of sound from different locations in said predetermined area to produce a sound mixture which confuses the identification of the source of said continuous, repetitive, pattern of sound; and,

maintaining said continuous, repetitive, pattern of sound at a sound pressure level sufficient to mask environmental sound.

7. A method of sound conditioning an area, comprising: producing a plurality of substantially parallel sound tracks on a carrier; each sound track comprising one cycle of sound primarily in the audible frequency range; the pattern of sound within said cycle having random variations of frequency and the patterns of sound on each track being substantially similar; arranging the sound tracks with a slight time lag in the beginning of the cycle on each track; simultaneously sensing the signals on all tracks, amplifying the signals and radiating the resulting sound patterns into said area to produce time-lag sound cycles; and successively and continuously repeating the sensing and radiating of said signals in the original time-lag relation to produce a continuous, repetitive, pattern of sound radiation in said area.