Question: Who is responsible for mixing the audio?
About the article "What Makes You Beautiful", section "Background and release".

Candidate passages:
A mix engineer or mixing engineer is a person responsible for combining ("mixing") the different sonic elements of a piece of recorded music (vocals, instruments, effects etc.)
into a final version of a song (also known as "final mix" or "mixdown").
He or she mixes the elements of a recorded piece together to achieve a good balance of volume, while at the same time deciding other properties such as pan positioning, effects, and so on.
The best mixing professionals typically have many years of experience and training with audio equipment, which has enabled them to master their craft.
A mixing engineer occupies a space between artist and scientist, using their skill at assessing the harmonic structure of sound to enable them to fashion highly appealing timbres.
Their work is found in all modern music, but many artists now mix and produce their own music with a digital audio workstation and a computer.
A more technical definition: an audio engineer in sound recording, audio editing and sound systems who balances the relative volume and frequency content of a number of sound sources.
Typically, these sound sources are the different musical instruments in a band or vocalists, the sections of an orchestra and so on. 
The Audio/Visual (AV) crew is responsible for stage, lighting, and sound for BMHS's theatre. 
A2 is an abbreviation for Audio Assistant, Second Audio Assistant, or Second Assistant Audio Engineer.
Any of these three terms, or any similar term such as Mic Wrangler, may be used to describe the same set of duties.
An A2 is a stagehand who is responsible for the upkeep, acquisition, and use of microphones, backstage monitors, communication systems, and the audio system.
There are typically one or two people with this job title associated with any major theatrical production making use of such audio elements.
The term "A2" refers to the fact that this person is frequently the second in command on all matters relating to sound during the performance, reporting directly to the Production Audio Engineer, or A1.
In addition to his or her own responsibilities, the A2 often acts as an understudy for the A1.
In touring theatre, the A2 is often responsible for overseeing the load-in of all backstage audio elements.
In musical theatre, the A2 may or may not be the technical liaison to the orchestra, and duties could include monitor mixing, placement and upkeep of microphones in the orchestra, and video feeds to and from the conductor. 
In sound recording and reproduction, audio mixing or mixdown is the process by which multiple recorded sounds are combined into one or more channels, for instance 2-channel stereo.
In the process, the source signals' level, frequency content, dynamics, and panoramic position are manipulated and effects such as reverb may be added.
This practical, aesthetic, or otherwise creative treatment is done in order to produce a mix that is more appealing to listeners.
Audio mixing is done in studios as part of creating an album or single.
The mixing stage often follows a multitrack recording.
The process is generally carried out by a mixing engineer, though sometimes it is the musical producer, or even the artist, who mixes the recorded material.
After mixing, a mastering engineer prepares the final product for reproduction on a CD, for radio, or otherwise.
Prior to the emergence of digital audio workstations (DAWs), the process of mixing used to be carried out on a mixing console.
Currently, more and more engineers and independent artists are using a personal computer for the process.
Mixing consoles still play a large part in the recording process.
They are often used in conjunction with a DAW, although the DAW may only be used as a multitrack recorder and for editing or sequencing, with the actual mixing being performed on the console. 
The audio department is responsible for all sound production for a show, including the configuration of microphones, speakers and control equipment, as well as the production of any necessary audio tracks.
Personnel in this department include: Sound designer or Audio Engineer, responsible for the configuration of the venue's sound system as a whole, including the placement and designation of microphones, monitors, loudspeakers, and control hardware.
This position is often held by an acoustician, especially in large performances requiring musical or orchestral sound reinforcement.
Sound operator, responsible for the live mixing of the performance's audio at a master sound board.
Often referred to as A-1 to designate the first (highest) position of the production Audio department.
This technician is generally positioned in the back of the audience space, so as to hear the performance's audio directly rather than be forced to use a monitoring system, and is responsible for maintaining volume for performers and musicians while avoiding feedback and other problems.
*A-2, or audio assistant, responsible for the maintenance and monitoring of audio equipment used by the sound operator (specifically any lavalier microphones used in the performance).
Depending on performance size, this technician may perform other duties, including the operation of audio media devices.
In smaller performances, this position is often taken by a stagehand rather than a technician trained in audio.