654 Royalty-Free Audio Tracks for "Belows"

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.

This is a sci-fi ambient drone sound i made. It's creative commons cc0, so please treat it as public domain. You can use it in any commercial or non-commercial media for free, no restrictions. For those curious how i made this, i took a quick 8-second drum loop from my pocket operator po-33 (ko) and ran it through a free time-stretching/pitch-shifting program called akaizer. The program's based on old samplers like the akai s1000 that had extremely artifact-heavy time-stretching and pitch-shifting features. If you slow a sound down enough, the final product tends to sound harsh and electric. Akaizer turned my 8-second drum loop into 2 minutes and 38 seconds of harsh, bassy noise, pretty damn close to the final. Then i imported the file (we'll call it file a) into reaper, my daw. Track 1 has reaeq with a high-shelf acting like a low-pass. Its curve is set at 1386. 2 hz, gain at -inf, and bandwidth at 2. In retrospect, i have no idea why i didn't use a low-pass. Track 1 has a send to a blank track 2, which has a fab-filter pro-q 3 high-pass filter with a 12db slope. It's at 320. 57hz, q is 1. 096. After the eq, track 2 has valhalla shimmer set to the black hole preset with no changes. Track 3 is the default file a with valhalla shimmer on the black hole setting, but with two tweaks. Low-cut is at 30hz, high-cut is at 6630hz. Everything else is the same. That's followed by fab-filter pro-q 3 with these eq settings:-0. 72db at 69. 463hz, q at 1. 007. -1. 11db at 536. 64hz, q at 1. 013, dynamic eq (click "make dynamic" and leave everything as-is). The point of this dynamic eq is to give a slight drop in gain in the 500hz region, which tends to get muddy in larger mixes. I wasn't sure if i'd use this for a larger project, and i didn't want build-up in that region from the already large-sounding track 1 and 2. The ocassional eq drops here also adds a warble to the final mix that helps sell an analog, electrical sound. +0. 85db at 3697. 3hz, q at 1. 009. This is to add subtle airiness to the drone. It seems weird to have "airiness" in the 3-4k region, but it's the sort of rumbliness of the sound traveling away and dissipating in the atmosphere after the lowest drone sounds. My volume fader settings for all 3 tracks:. Track 1: -8. 59 dbtrack 2: -6. 46 dbtrack 3: -6. 43 db. On my master bus, i have izotope imager 9 with these settings:. Band 1: width at -100 (mono) for 59hz and below. Band 2: nothing at 60hz to 525hz (width at 0). Band 3: width at 48. 1 for 526 to 1. 4khz. Band 4: width at 49. 4 at 1. 4khz and above. Stereoize is set to 6. 4ms on mode i. And that's it! no compressors or limiters anywhere, since i liked how dynamic the actual tracks were and i figure you can always add your own compressor or limiter to the final if you want. I've also added the original po-33 drum loop on my page, as well as the loop after it was run through akaizer but before it hit reaper in case you want to do your own processing. Enjoy :).

Start sound of mac ii iix iicx iici se/30. Create by dissessemble rom code and use wave table algorithm write c program write wav file. C program below:. /* mac_ii. C *//* boot beep mac ii *//* 2558/09/06 */. #include. #define knumber_samples 30000#define kdelay_note 300#define kwave_table_value 0x30013f10#define ksample_rate 22257 // hz. Void preparewavetable( unsigned short *wavetable, unsigned int value );void updatewavetable( unsigned short *wavetable, unsigned short chiso );void savesound( char *filename, short *sounddata, unsigned int numberframes, unsigned int samplerate );. Int main () {. // ---- wave tableunsigned short wavetable[256];// ---- sound data, stereoshort sounddata[knumber_samples << 1];// ---- increment array (16/16 bit fix point integer)int arrayincrement[] = {3 << 16, 4 << 16, (3 << 16) + 0x2f2, 6 << 16};// ---- prepare wave tablepreparewavetable( wavetable, kwave_table_value );. // ---- array phase (16/16 bit fix point integer)unsigned int arrayphase[] = {0, 0, 0, 0}; // set all = 0. Unsigned int samplenumber = 0;while( samplenumber < knumber_samples ) {. // ---- calculate sampleunsigned int channelleft = 0;unsigned int channelright = 0;unsigned char notenumber = 0;while ( notenumber < 4 ) {// ---- see if should update phase for note, only do if play noteif( samplenumber >= notenumber*kdelay_note ) {// ---- up date phase beforearrayphase[notenumber] += arrayincrement[notenumber];// ---- not let out of range [0; 255]if( arrayphase[notenumber] > 0xff0000 ) // 0xff0000 == 255 << 16arrayphase[notenumber] -= 0xff0000; // return to begin of wave table}unsigned short mauvat = wavetable[arrayphase[notenumber] >> 16];. // ---- add sound componentsif( notenumber < 2 ) // ---- first 2 notes left channelchannelleft += mauvat;else // ---- last 2 notes right channelchannelright += mauvat;// ---- next notenotenumber++;}// ---- save left and right samplessounddata[samplenumber << 1] = (channelleft << 9) - 0x8000; // use << 1 for 16 bitsounddata[(samplenumber << 1) + 1] = (channelright << 9) - 0x8000; // use << 1 for 16 bitupdatewavetable( wavetable, samplenumber & 0xff );samplenumber++;}// ---- save wav filesavesound( "mac ii. Wav", sounddata, samplenumber << 1, ksample_rate ); // multiply 2 because stereo. Return 1;}. Void preparewavetable( unsigned short *wavetable, unsigned int value ) {. // ---- prepare wave tableunsigned short index = 0;unsigned short wavetablevalue = value & 0xff;while( index < 64 ) {wavetable[index] = wavetablevalue; // << 8; // for 16 bitindex++;}. Wavetablevalue = (value >> 8) & 0xff;while( index < 128 ) {wavetable[index] = wavetablevalue; // << 8; // for 16 bitindex++;}. Wavetablevalue = (value >> 16) & 0xff;while( index < 192 ) {wavetable[index] = wavetablevalue; // << 8; // for 16 bitindex++;}wavetablevalue = (value >> 24) & 0xff;while( index < 256 ) {wavetable[index] = wavetablevalue; // << 8; // for 16 bitindex++;}}. Void updatewavetable( unsigned short *wavetable, unsigned short index ) {// ---- get value from wave tableunsigned short value = wavetable[index];// ---- calculate new value for wave tableif( index == 255 ) { // careful at last element of wave tablevalue += wavetable[0];value = (value >> 1);wavetable[0] = value;}else {value += wavetable[index+1];value = (value >> 1);wavetable[index+1] = value;}. }. #pragma mark ---- save wavvoid saveheader( file *filename, unsigned int samplerate );void savesounddatainteger16bit( file *filename, short *sounddata, unsigned int numbersamples );. Void savesound( char *filename, short *sounddata, unsigned int numberframes, unsigned int samplerate ) {// ---- open filefile *file = fopen( filename, "wb" );if( file ) {// ---- "riff"fprintf( file, "riff" );// ---- length sound file - 8unsigned int lengthsoundfile = 32;lengthsoundfile += numberframes << 1; // một không có một mẫu vạt cho kênh trái và phải// ---- save file lengthfputc( (lengthsoundfile) & 0xff, file );fputc( (lengthsoundfile >> 8) & 0xff, file );fputc( (lengthsoundfile >> 16) & 0xff, file );fputc( (lengthsoundfile >> 24) & 0xff, file );// ---- "wave"fprintf( file, "wave" );// ---- save headersaveheader( file, samplerate );// ---- save sound datasavesounddatainteger16bit( file, sounddata, numberframes );// ---- close filefclose( file );}else {printf( "problem save file %s\n", filename );}}. Void saveheader( file *file, unsigned int samplerate ) {// ---- name for header "fmt "fprintf( file, "fmt " );// ---- header lengthfputc( 0x10, file ); // length 16 bytefputc( 0x00, file );fputc( 0x00, file );fputc( 0x00, file );// ---- method for encode, 16 bit pcmfputc( 0x01 & 0xff, file );fputc( (0x00 >> 8) & 0xff, file );// ---- number channels (stereo)fputc( 0x02, file );fputc( 0x00, file );// ---- sample rate (hz)fputc( samplerate & 0xff, file );fputc( (samplerate >> 8) & 0xff, file );fputc( (samplerate >> 16) & 0xff, file );fputc( (samplerate >> 24) & 0xff, file );// ---- number bytes/secondunsigned int numberbytessecond = samplerate << 2; // multiply 4 because short (2 byte) * 2 channelfputc( numberbytessecond & 0xff, file );fputc( (numberbytessecond >> 8) & 0xff, file );fputc( (numberbytessecond >> 16) & 0xff, file );fputc( (numberbytessecond >> 24) & 0xff, file );// ---- byte cho một khung (nên = số lượng mẫu vật * số lượng kênh)// ---- number bytes for sampleunsigned short bytesoneframe = 4; // short (2 byte) * 2 channelunsigned char bitsonesample = 16; // shortfputc( bytesoneframe & 0xff, file );fputc( (bytesoneframe >> 8) & 0xff, file );. Fputc( bitsonesample, file );fputc( 0x00, file );}. Void savesounddatainteger16bit( file *file, short *sounddata, unsigned int numbersamples ) {fprintf( file, "data" );unsigned int datalength = numbersamples << 1; // each sample 2 bytefputc( datalength & 0xff, file );fputc( (datalength >> 8) & 0xff, file );fputc( (datalength >> 16) & 0xff, file );fputc( (datalength >> 24) & 0xff, file );unsigned int sampleindex = 0;while( sampleindex < numbersamples ) {short shortdata = sounddata[sampleindex];fputc( shortdata & 0xff, file );fputc( (shortdata >> 8) & 0xff, file );sampleindex++;}}.

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.