247 tracce audio royalty-free per "Due"

I was surprised this still worked. This is an old ibm selectric ii typewriter, with correcting tape, the “quieter” selectric at the time. It’s about 80 pounds, a real back-breaker. The carriage return bell is broken, unfortunately, so the best you might hear it is rattling due to the belt vibration. Recorded with a tascam dr-05, without the low-cut since i wanted a beefy sound. Placed direcly above the roller, about 12 inches away. I swapped the channels in audacity to match perception & sampled down to 48khz. Description: i roll in some paper, type a few paragraphs from some copy, and roll it out when i’m done. Man, can you type fast on these machines!.

Sound recording of a two tier mini waterfall into my small fish pond. Recorded with a tascam dr-07 mk ii. 24 bit, 44. 1 khz, stereo. First 10 seconds is the raw recording. Note the 60 hz hum due to the water pump being just under the water fall splash area. The last 20 seconds is the processed audio using ableton live 8 affects rack and the following affects. 1. Notch filter – 60 hz applied two times. 2. Lp filter –knee at 1 khz3. Hp filter-knee at about 3. 2 khz4. Granular delay – bubbling sound5. Chorus audio effect-snap, crackly sound. 6. Reverb-cave echo affect-high wet/dry7. Utility- for stereo width.

Yanmar boat engine sound during voyage near island vis.

Yanmar boat engine sound during voyage near island vis.

Yanmar boat engine sound during voyage near island vis.

Yanmar boat engine sound during voyage near island vis.

Countdown from 3 to 0.

Sound of two clocks, one close and the other far from the mics, recorded with a roland r-26. Let me know if you need 4 channels (from directional and omnidirectional mics), this is a stereo mix of both.

Boomerang is a steel shuttle roller coaster located at bellewaerde in ypres, west flanders, flemish region, belgium. Although it wasn't the first vekoma boomerang to be built, it was the first to be opened due to technical issues with the other roller coaster. This spectacular roller coaster takes you to a height of 32 m, before launching you forward and backward, like a boomerang, at over 80 km/h. There is a lot of nonsense in this file. Some belgian teenagers are talking about their families, their teachers, to fall out of the coaster, banana, carrot. . . You can even hear some flemish words. Recorded inside the roller coaster with tascam dr-100mkii onboard microphones.

Recording of sea undertow on the beach of formicoli, vibo valentia, calabria, italy, the 19th agust 2022 16:44. The sound was recorder with a zoom h1n with windshield at a short distance from the crashing of the waves on the beach. The waves are driven by a light, gentle wind. The sound was recorded by holding the microphone in my hand while i dived knee-deep into the water and walk, filming the crashing of the waves (also on my legs). High-frequency sound details (the foam of the sea, the impact of waves on each other, etc. ) are much more audible here. Processing:* volume adjustment;* 120hz high pass filter (to reduce low some low frequencies rumble due to the wind);* cut and crossfade to eliminate very few mechanical noise of my hand on the mic;.

(recorder: zoomh4npro 2018)(microphones: zoomh4npro 2018 on-board microphones). This is a recording of illegal fireworks being launched all over los angeles on the 4th of july, 2020. All surface to air fireworks are illegal but, due to covid-19 cabin fever, people just didn't care this year. This recording is almost 99% voice free. There was a couple on a balcony that are barely heard muttering something in just a minute or two of this recording. For the most part, it's clean. I kept the peaks very low to maintain a natural sound. All of my sounds recordings are provided free of all charges. I give all rights to the down-loader for any purpose either personal or commercial. Enjoy!. Christopher c. Courter.

brrraaattt! - male - vocal chant - two takes.

Hello and welcome everyone from istanbul. This is emin. I'm really happy if you like my audio recordings and sound effects. I'm trying so hard to improve myself on this. I'd really appreciate it if you'd like to support me. Thanks. Litecoin (ltc) adresslftxm1w4p8w7yrh69ppwffb2bnsqczebbg. **i'm sending my personal archive to everyone who donated.

This is a news piece done by chris fox for kews radio. The story has to do with the two church fires in greenville texas.

Reunion Dues performed by The USAF Band Airmen of Note

This is an alternate recording i took on 04/26/2014, on microcassette, of an art installation in madison, wi titled "asylum," created by marina kelly and megan katz. This was taken at the same time as the cassette recording i uploaded previously; if asked by kelly or katz i will respectfully take both down. "asylum" was a temporary art installation located in the tenney park passageway under east johnson street. From what i saw when i was there, it was just a speaker or two playing some ambient sounds. These sounds could have been generated based on environmental input, but due to lack of evidence i can't conclusively say that was indeed the case. I was in a bad mood on this recording so apologies for the negativity/language.

A recording i took on 04/26/2014, presumably on cassette tape, of an art installation in madison, wi titled "asylum," created by marina kelly and megan katz. To my knowledge, this is the only audio recording that exists of the soundscape, though if asked by kelly or katz i will respectfully take it down. "asylum" was a temporary art installation located in the tenney park passageway under east johnson street. From what i saw when i was there, it was just a speaker or two playing some ambient sounds. These sounds could have been generated based on environmental input, but due to lack of evidence i can't conclusively say that was indeed the case. I was in a bad mood on this recording so apologies for the negativity/language.

This was created with reaktor 6, nested inside vcvrack (via the "host" module) run through various effects in vcv rack. Ultimately this was rendered out at 192khz (vcv allows for very high super sampling). Many frequencies that are above the range of hearing exist in this file due to rendering it at such a high sample rate. I recommend that, in your daw of choice: pitch this down a couple octaves while running this through a frequency analyzer. Watch how many notes and tones emerge into the range of hearing. You might need a high shelf eq on this as well as a slight high pass filter. Several use cases for this sound: in the background of a sci-fi video game. On your next ambient dark drone top 40 hit single. Run through effects like granulators, pitch shifters and spectral distortions to make a crazy sound design sculpture.

A rather lengthy sound byte that i heavily edited to the point of being unrecognizable. It sustains a flat note with varying bass levels causing an unnerving effect or the listener or player. I had designed this track for a roleplay plot involving a cursed train station, the plot came out kinda rough and it fell through midway. . . But, the audio track i made came out good enough to post here like my first sound involving my transformers oc!. It's free to use as long as you credit me, and it can be used in a wide variety of fields that is deemed appropriate. From suspense to horror, or even background noise in a lighter field; it can be altered and edited as needed due to it's broad and simple design. I made the volume low to prevent any extreme bass causing ear bleeds. Hope you enjoy! <3.

Better set on monoaural on your daw if possible due to the off-center recording. Having been a bit ill on some rich iron content food i couldn't stomach (offal it was, it was the sheep fried liver who was the culprit - the very rich iron content upset my stomach pretty bad - was looking for something "new". ). Keep in mind that i am unable to do this as a request for obvious reasons including health, livelihood and risk of damage to equipment. I tried very hard to avoid shaking the zoom as not to make the wobbling sounds. If i am ill again, i'll use my ma-2 (microphone stick) and gravity microphone stand and get a real good recording of real vomiting but keep in mind this was recorded in my showerroom so some er may occur.

brrraaattt! - male - vocal chant - two takes loudly.

Sound originally recorded by enjoypa. Edited to exactly 60bpm.

Another recording of rain and thunder, but in some ways a better one. This one is a surprisingly big crack and rumble preceded and followed by a nice sounding rain. I made this by positioning a stereo-matched pair of akg c451b condenser mics in an exaggerated x-y configuration (a wider stereo field) and aiming them out of my open window. The mics went into a universal audio 2-610 preamp, an apogee duet 2, and then ableton at 48khz and 24 bits. I believe i had the mics set flat, and there was no post processing (though i was mightily tempted to upload the much-better-sounding eqed and compressed files) so that you can fine tune it to suit your needs. You'll notice that the loudest parts of the thunder boom clipped the input, but, due to the pleasant and forgiving nature of vacuum tubes, the clipping sounds more compressed than distorted. Feel free to use this sound in any commercial or artistic work! you do not need to credit me.

This sound file incorporates sounds from freesound. Org due to the pandemic at hand and not being able to go out and record these sounds individually. The addresses i chose are sportsman’s park racetrack (cicero) and mission hills golf club. I made a substitution with one sound file that i recorded myself in nature in my neighborhood to incorporate the sounds of a golf course. Although the other file was used from freesound. Org. This piece uses these sounds from freesound: vw golf r, by everydaysounds. Additionally, what can be heard on this file is the sounds of birds chirping and rain falling as well as the sound a fast car speeding around a track to propose some contrast. Something that could spark the listener’s interest is that not often does nature and the machines that we humans make harmonize with each other, but in this i think they flow just fine. Https://freesound. Org/people/everydaysounds/sounds/268622/.

Zoom h4n 2018 - onboard microphones. This recording is 17 full minutes of ambiance from inside an in-n-out fast food restaurant. This in-n-out is located in downtown burbank, california located at 761 n 1st st, burbank, ca 91502. The great thing about this recording is that it's free of all music that would invalidate the recording due to copyright restrictions. In-n-out, unlike other fast food chains, does not allow music in their dining rooms. This is because most in-n-out locations are so busy and constantly loud, the addition of music would create an unbearable sense of mayhem. So, rest assured you may use this ambiance in your project with no restrictions!. The beginning of the recording starts during a busy lunch hour. As the recording progresses, the announcements on the intercom stop and things become a bit more calm. Enjoy!. - christopher.

brrraaattt! - male - vocal chant - two takes quietly.

Another sound effect for when a user clicks on an button in a menu; this one has a sci-fi effect to it. It has two different "click" sounds, i should soon upload a sound effect with just a single click. Enjoy!. Have a great day!. P. S. I request that all my sound effects only be used for clean, appropriate media and projects. Thanks!.

04-21-2013 - chainsaw cutting:sunday, april 21, 2013: had to take care of some fallen trees; seemed wise to record it. This chainsaw is brand new. 45cc recording taken at a distance of 30 feet and is unfortunately tarnished at the front with an ambulance siren. Recording gear: zoom h2/n @ 44. 1k/16bit using built-in xy microphones.

Just a few numbers counted from a vocaloid voice pack set.

Two people snowshoeing on hard packed snow, one wearing neoprene snow pants. File sounds much less compressed when downloaded. Some intermediate wind sound and distant voices. Recorded on an olympus ls7 portable digital recorder.

Several years back my older brother stumbled upon a bunch of old family reel to reel films and sat down one evening to project them on a wall and digitize them. This is the sound of that process. What you can hear, i imagine, is the noise of the projector in the left channel and the sound of the reels in the right channel. I've been obsessed with the sounds of the infinite variation in old analog hardware. As a sound designer, that infinite variation is often sought after but rarely, or accurately, reproduced through digital files in various libraries. Of if they are, they're often too short to cover whatever scene i am trying to fill. On the surface it's just noise but if you listen closer it's this wonderful cacophony of overlapping and repeating sounds that are always looping but never quite identical on each rotation. It was ripped from youtube using audio hijack at 48khz/16bit, but due to youtube re-encoding things as youtube does, it's nowhere near the source. It's still, in my opinion, a sound worth sharing. Enjoy!.

This recording is for people who hate the highlighted high frequencies. An old sabian aax small recorded with a røde m5 mic. I the created two copies of the original recording:1. On the first file i applied low pass at 2 khz and hard compression at -24 db without makeup gain. 2. On the second file i applied high pass at 2 khz and hard compression at -24 db without makeup gain. Then i lowered -2 db all the spectrum except for the band from 3. 5 khz to 9. 1 khz and i applied hard compression at -24 db without makeup gain. I merged the two files. The envelope was very flat due to the compression and thus i reshaped it on wavelab (process > level envelope. . . Or press the "v" keyboard button; draw a natural fade out in steps [non-linear]). The result is a warm crash for people who don't want them loud.

Spoken countdown sequence with the words "five four three two one fire" recorded and edited in audacity.

The sound is coming from the fans of a server. By pulling out one of the fans, all other fans turn up to 100%. The microphone is located above the air duct exactly in the middle of the case and thus between two fan fronts. The soundfile starts with the fans on standard speed. After a few seconds the fans turn up to 100%. I left them there for a few seconds and then quietly plugged the removed fan back in. This fan now also switches to 100% - this is the single, delayed "speed up" that can be heard from second 35. About 10 seconds later, all fans return to normal speed. Unfortunately, a colleague came in at that time and ended up talking into the recording. Due to lack of time, i was unfortunately unable to repeat the audio that day, but will certainly do another re-recording in the future. Feel free to use the sound; no attribution required. Feel free to write me in the comments what you used the sound for. Equipment:røde lavalier microphonesound devices mixpre-3 ii. File:wavmono96 khz32-bit float.

For free.

Female counting from 1 to 4, cut from a file downloaded from mp3bear. #counting #vocal #female #woman.

Please comment and rate!. I used audacity to put this together for a school project. I did use other sounds from this site and i will give credit where credit is due. This piece is a little lengthy and the last minute to minute and a half are not really needed, just for a transition. -thunderstorm: rhumphries at http://www. Freesound. Org/people/rhumphries/sounds/2523/. -alarm warning: guitarguy1985 at http://www. Freesound. Org/people/guitarguy1985/sounds/59864/. -shooting(1): alienbomb at http://www. Freesound. Org/people/alienbomb/sounds/39065/. -shooting(2): omar alvarado at http://www. Freesound. Org/people/omar%20alvarado/sounds/96533/. -shooting(3): cam. Dudes at http://www. Freesound. Org/people/cam. Dudes/sounds/113360/. -airplane: bram at http://www. Freesound. Org/people/bram/sounds/11687/. -airstrike explosion: omar alvarado at http://www. Freesound. Org/people/omar%20alvarado/sounds/93741/. -editing program: audacity at http://web. Audacityteam. Org/. I would like to give thanks for all the people who uploaded their great sounds, i hope people find my battlefield sounds useful in many ways. Special thanks to: rhumphries, guitarguy1985, alienbomb, bram, cam. Dudes and omar alvarado especially. Please message me if you are to use this in a video or presentation. Thanks. -2school4kool.

Counting 1 to 10 - australian female voice. Recorded with zoom h4n pro.

Català: Zarabanda de Johan Kuhnau on es pot veure una forma binària de dues frases

This intro was produced for the german "grinkenschmidter winterfest 2018" show and is now available for you. Text:ladies and gentlemen - may i have your attention please!the show starts in ten - nine - eight - seven - six - five - four - three - two - one - go. -----------------------------------------------due to recent events i would like to share this statement with you:no, i did not sold this countdown sample. It was - and of course still is - cc0 licenced and you are allowed to use it anywhere. If you receive a copyright claim from youtube or someone else this is generally because people used it in their productions and distributed them commercialy, which is ok, because this sample is cc0 licenced. But the "content id scanning system" of youtube thinks by mistake that the distributor is the exclusive copyright holder of that sample/track. Such systems are prone to errors and will probably never work perfect. . . If you run into such issue, please dispute the copyright claim and refer to this sample on freesound. Org and the cc0 licence:http://creativecommons. Org/publicdomain/zero/1. 0/. Regarding to all my sounds you are really safe when you do this and if you require any further assistance please do not hesitate to contact me!. You can find more information here:https://freesound. Org/help/faq/#a-freesound-sound-i-used-in-a-youtube-video-got-copyright-claimed-what-should-i-do-----------------------------------------------.

Re: http://www. Freesound. Org/forum/sample-requests/32458/.

Recorded my son (age 4) counting to 10.

Respuesta impulsional de una sala grande, con el techo haciendo pendiente hacia los dos costados recubierto de madera, distintas estanterías, muebles, sofás,. . . En la pared lateral derecha hay distintas ventanas con cortinas, mientras que en la otra pared hay dues puertas (una de vídrio).

If there is one man, white western historyhas neglected, it must be james baldwin (1924 - 1987)known to many as writer, novellist, essayistplaywright, poet. . . Surely unknown to all asactivist, as frontfighter, as luchador of theanti-xenophobic anti-discrimination discoursin general & more specific of the north-american'negro'. His father was a slave & as a childat the tender age of 10, he was teased and abusedby 2 new york police officers, an instance of the racistharassment by the nypd that he would experience againas a teenager and document in his essays. Why isn't his history & discours teached at school ?. Anno 2020, i learn to know him & his eloquent rhetoricalcapabilities through the also fenomenal moving & breath-takingperformance of tawiah + myrrh for the refraction festival, takingplace online of course, due to the ever infamous covid-19. . . An audiovisual délice, in which visual artist myrrh, places tawiahin subtle superposition with james baldwin & his 1965 debate with mr. Buckley ! in the cambridge union ! !! ! ! ! while performinglive one of the most delicate concerts i have seen during corona. . . A must see+hear _ _ _ https://www. Youtube. Com/watch?v=h5l2lssdzro. Being totally absorbed by this performance, i discover as an artist myselfone of the reasons i bind so much with this piece of music is that i myselflike to use the same harmonies, apparently, which i did indeed in 2015https://soundcloud. Com/torturado/eternal-void-the-fall-back& in the mid nineties, that is 1990's. . . A long forgotten piece of me, performed that time during my ritcs studies, as my band torturado, no recordings from then helas online, but gracias a la discovery of tawiah+myrrh & james baldwin picked up again what i remembered from that time & made a 2020 version of it. . . A small visual document of this: https://vimeo. Com/450004585. As from the moment, i discovered james baldwin, i integrated also his powerful 1965 debate in my performances during covid times. . . To spread his word ! to inspire others, to confront others. . . I told myself covid or corona is not going to stop me playing & performing music, which comes natural to me, so i looked for ways to perform outside, in plain nature, with batteries. . . Guitars, 9v fx, fx without 9v compartment, battery based amplifiers, battery based kassette walkmans. . . & it is on kassette that i put an edited full version of the james baldwin vs buckley debate of 1965. . . For this exercice of the sound design formation, we had to upload a sound that intrigues, well, james baldwin eloquent voice, litteral & metaphorically inspired & triggered me. . . Also the sound of electro-magnetic technology called tape is something i have always been fond of. . . So i made an edit of an edit of the james baldwin debate of +- 10 minutes !. Spread the word !a+. Actually this could also serve the exercice of recording a sound that comes from a certain place, or is part of a bigger thing , or personificates a certain place. . .

A few cycles of my dad's home oxygen machine with a ticking battery operated clock in the background recorded in the early morning in the living room with lifecam hd3000 webcam at the end of about 16 feet of usb cable dragged out of my bedroom. He's about 6 feet away, i was with my back to the room with my camera pointed at my chest so he wouldn't think i was filming. It would seem this is the first and only oxygen machine on freesound. A full cycle seems to last from between 7 to 10 seconds. From wikipediaoxygen concentrators typically use pressure swing adsorption technology and are used very widely for oxygen provision in healthcare applications, especially where liquid or pressurised oxygen is too dangerous or inconvenient, such as in homes or in portable clinics. Oxygen concentrators are also used to provide an economical source of oxygen in industrial processes, where they are also known as oxygen gas generators or oxygen generation plants. Oxygen concentrators utilize a molecular sieve to adsorb gasses and operate on the principle of rapid pressure swing adsorption of atmospheric nitrogen onto zeolite minerals and then venting the nitrogen. This type of adsorption system is therefore functionally a nitrogen scrubber leaving the other atmospheric gasses to pass through. This leaves oxygen as the primary gas remaining. Psa technology is a reliable and economical technique for small to mid-scale oxygen generation, with cryogenic separation more suitable at higher volumes and external delivery generally more suitable for small volumes. [1]at high pressure, the porous zeolite adsorbs large quantities of nitrogen, due to its large surface area and chemical character. After the oxygen and other free components are collected the pressure drops which allows nitrogen to desorb. An oxygen concentrator has an air compressor, two cylinders filled with zeolite pellets, a pressure equalizing reservoir, and some valves and tubes. In the first half-cycle the first cylinder receives air from the compressor, which lasts about 3 seconds. During that time the pressure in the first cylinder rises from atmospheric to about 1. 5 times normal atmospheric pressure (typically 20 psi/138 kpa gauge, or 1. 36 atmospheres absolute) and the zeolite becomes saturated with nitrogen. As the first cylinder reaches near pure oxygen (there are small amounts of argon, co2, water vapour, radon and other minor atmospheric components) in the first half-cycle, a valve opens and the oxygen enriched gas flows to the pressure equalizing reservoir, which connects to the patient's oxygen hose. At the end of the first half of the cycle, there is another valve position change so that the air from the compressor is directed to the 2nd cylinder. Pressure in the first cylinder drops as the enriched oxygen moves into the reservoir, allowing the nitrogen to be desorbed back into gas. Part way through the second half of the cycle there is another valve position change to vent the gas in the first cylinder back into the ambient atmosphere, keeping the concentration of oxygen in the pressure equalizing reservoir from falling below about 90%. The pressure in the hose delivering oxygen from the equalizing reservoir is kept steady by a pressure reducing valve. Older units cycled with a period of about 20 seconds, and supplied up to 5 litres per minute of 90+% oxygen. Since about 1999, units capable of supplying up to 10 lpm have been available.

No pain no gainshort storyby: maqsood hasnitranslated by: najamfree abuzar barqi kutab'khanafeb. 2019owing to the intensity of heat and thirst, the crow was very enervated but there was no water and shade. He went on roaming about in search of water. He was thinking that, he would definitely die, if he could not find water in a short time. He neither wanted to die nor he was disappointed. He was determined to seek water and shady tree till the last breath of his life but, in fact, the intensity of thirst was creating problem for him. Now he had two choices either he must continue seeking water or leave it and wait for death. He mustered courage and flew east in search of water. He had covered a short distance when he saw a garden and hurriedly started flying towards it he wanted to live and was sure of hisexistence in future. Quite surprisingly, he seemed to be more active now. He wanted to reach the garden very soon and every cost. Though he was flying very speedily yet the garden seemed to be very far off. He got tired and thought that the garden be an illusion of his mind. He was shaken about the entity of garden. He thought it might be an illusion and he must seek any other way which could rescue his life. But he had not any other choice. To chase the illusion was better than to leave seeking water because there was the possibility of life. If he died while searching, it would be a courageous step. He stopped for awhile and the garden was quite at short distance. He hopefully started marching towards the garden and felt that it was not too far. He felt grief for wasting a precious moment. He would have been ahead if he had not stopped. He felt ashamed ofhis negative thinking because they could bring about demise. These negative feelings were equal to pessimism. A devoted definitely finds his goal at last because god helps those who helpthemselves. He took on fling with great zeal and now he appeared to be fresh. He was spiritually exalted and was flying without difficulty. Now he reached the threshold of the garden. The garden was in the urban area and it meant that it was for pastime but he was surprised to see that there were no bower. Birds had left this garden when men himself neglected it. He flew over the garden but there was no water. He deplored his labor. Suddenly, he found a pitcher in the garden and felt rejoiced and hurriedly went to it. There was very little water in the pitcher and he made very attempt to drink water but failed due to the low level of water. He hatched a plan and caught a pebble with the help of his beak and put it into the pitcher. Owing to heat, the pebble was dry and it seemed that it had liked it. In a short time, the crow poured another pebble and the first pebble did not like this sharer. Although it had not liked thesecond one yet the bitter fact was that the wise crow imposed his will by throwing more pebbles into the water. The crow was gallantly doing his job and, at last, the pitcher became full of wet pebbles and he drenched his thirst by sucking wetness of them.

Recorded in my dad's bedroom with lifecam hd3000 webcam. This is a much better recording than my previous oxygen concentrator file, as i hauled my desktop into the bedroom at the other end of the apartment where the machine now is, when i was home alone. The webcam is on the bed about 3 or 4 feet from the machineat the beginning of the file you hear me flip the big switch and the machine comes on with a long on beep and thumps. I edited it to start then. At 00:1. 8 what i suspect is the water pump comes on, though i may be wrong. That's when the gurgling starts though. The machine has a small reservoir for distilled water to moisten the airflow. A cup or two lasts several daysyou'll hear various hisses and thumps in a 15. 6 second cycle as it runs. At 03:03 i flip the big switch to shut the machine off, and it bubbles and gurgles away for the rest of the file, as water i assume slowly perculates back into the reservoir, the bubbling getting quieter and quieter until it doesn't even sound like bubbling anymore, until it finally ticks to a stop. At 03:16 you hear me step as i get my foot loose from the mic cord lol. At 04:13 the furnace shuts down as a car finishes going by outside in the bass register, faint traffic noises and the furnace being the only background noises you'll hear aside from my moving around a couple times, and a faint bluejay at the end. At about 07:00 you can barely hear the machine anymore, but i could hear a faint ticking with my own ears. At 07:04 the furnace comes back on. At 07:08 you'll hear a bluejay faintly calling outside and a car going by outside after, which finishes the file at 07:20. I edited out my walking to the computer to shut the recording down. From wikipediaoxygen concentrators typically use pressure swing adsorption technology and are used very widely for oxygen provision in healthcare applications, especially where liquid or pressurised oxygen is too dangerous or inconvenient, such as in homes or in portable clinics. Oxygen concentrators are also used to provide an economical source of oxygen in industrial processes, where they are also known as oxygen gas generators or oxygen generation plants. Oxygen concentrators utilize a molecular sieve to adsorb gasses and operate on the principle of rapid pressure swing adsorption of atmospheric nitrogen onto zeolite minerals and then venting the nitrogen. This type of adsorption system is therefore functionally a nitrogen scrubber leaving the other atmospheric gasses to pass through. This leaves oxygen as the primary gas remaining. Psa technology is a reliable and economical technique for small to mid-scale oxygen generation, with cryogenic separation more suitable at higher volumes and external delivery generally more suitable for small volumes. [1]at high pressure, the porous zeolite adsorbs large quantities of nitrogen, due to its large surface area and chemical character. After the oxygen and other free components are collected the pressure drops which allows nitrogen to desorb. An oxygen concentrator has an air compressor, two cylinders filled with zeolite pellets, a pressure equalizing reservoir, and some valves and tubes. In the first half-cycle the first cylinder receives air from the compressor, which lasts about 3 seconds. During that time the pressure in the first cylinder rises from atmospheric to about 1. 5 times normal atmospheric pressure (typically 20 psi/138 kpa gauge, or 1. 36 atmospheres absolute) and the zeolite becomes saturated with nitrogen. As the first cylinder reaches near pure oxygen (there are small amounts of argon, co2, water vapour, radon and other minor atmospheric components) in the first half-cycle, a valve opens and the oxygen enriched gas flows to the pressure equalizing reservoir, which connects to the patient's oxygen hose. At the end of the first half of the cycle, there is another valve position change so that the air from the compressor is directed to the 2nd cylinder. Pressure in the first cylinder drops as the enriched oxygen moves into the reservoir, allowing the nitrogen to be desorbed back into gas. Part way through the second half of the cycle there is another valve position change to vent the gas in the first cylinder back into the ambient atmosphere, keeping the concentration of oxygen in the pressure equalizing reservoir from falling below about 90%. The pressure in the hose delivering oxygen from the equalizing reservoir is kept steady by a pressure reducing valve. Older units cycled with a period of about 20 seconds, and supplied up to 5 litres per minute of 90+% oxygen. Since about 1999, units capable of supplying up to 10 lpm have been available.