Thursday, December 4, 2014

Promo Video: March Of The Rads & Radioatomic Playlist

Delayed somewhat due to a reformat of the studio computer, here is the promo video for March Of The Rads: the opening atmosphere from the Radioatomic album.


Technical commentary about the audio can be found in this post. The video features footage from one of my favourite locations: the abandoned diatomite quarry. It has featured in many of the posts on this blog, many of my videos, and in my cover photography. The footage used here was collected over a period of three years, with the wobbling bar and yours truly walking in the foundations being among the most recent.

This being the final promo video for the Radioatomic material, I've grouped them all into a playlist that follows the album's running order. The only tracks not included are the two versions of '96MHz,' which I didn't feel needed illustrating. When you have a spare hour and eight minutes, why not give it a spin?


Wednesday, November 12, 2014

Promo Video: A Robot In Every Home

I'm currently completing the extant promo videos for the Radioatomic album. Here's A Robot In Every Home. This time I tried my hand at mixing stock footage with footage from the studio. Up until now the two styles have been kept separate. I sourced scenes from three public domain films: Leave It To Roll-Oh, The Middleton Family At The New York World's Fair, and The Last Word In Dishwashing. Studio footage includes my trusty tin robot Mini Radiocon, the Parker Brothers' Merlin game, the Roland HS-60, and Novation K-Station.

To give you an idea how much effort goes into these promo videos, I devoted one to two hours to the editing each evening over the course of a week. The studio footage was accomplished in a couple of afternoon sessions, and sourcing and converting digital film stock about the same again. Rendering the finished film took roughly six hours. It would go quicker, but my system isn't optimal for the task.

So, without further ado, let's see what kind of future we might've had if atomic power was all it was cracked up to be ...

Video:


Sunday, November 9, 2014

Field Recordings: City Junkyard

As I've mentioned in previous posts, I take a Zoom H1 digital recorder with me pretty much everywhere I go. My job often presents opportunities to record all sorts of interesting sounds. I also have an affinity for junkyards, and waste places where junk accumulates, and seek these out in my free time. They also offer up photo opportunities, and a lot of my album artwork is shot in these locations.

This summer I was able to visit a site that was new to me: the city junkyard, which is hidden from prying eyes behind the city gravel pit. This is home to anything the City Works dept. doesn't have room for in their yard: lengths of various sized pipe and culvert, pieces of machinery and equipment that are obsolete or 'in reserve,' temporary signage posts, old electrical boxes, pumps, dump-trucks in various states of disrepair, giant petrol tanks (the kind usually buried beneath petrol stations), and miscellaneous other odds and ends. It all adds up into junk heaven for someone like me.

One of many electrical boxes left to the elements.
I spent a couple of hours going from one end to the other with my camera, digital recorder, and my trusty striker: a valve rod from a car engine. I mostly concerned myself with the various lengths of pipe, many of them over a foot in diameter. One of the coolest sounds I captured was throwing pebbles into the largest of these. The giant petrol tanks were also a source of impressive sounds.

Pipes!
I found that placing the microphone in the mouth of the pipes yielded the most interesting results: it picked up the optimum amount of reverberation. The mic placed in front, a foot or so distant, gives a subtler effect, and above merely accentuates the sound of the striker.

More pipes!
Among the iron/steel pipes were some of comparable size made of thick plastic. These produced good pinging echoes. If you've ever tapped on an irrigation pipe you'll know what I mean. They're somewhat tricky to record at a decent volume, so more experimenting is in order!

The end of the larger petrol tank. Both were largely obscured by brush.
A little about the petrol tanks. There are two at this particular location, and both, as far as I could tell, were sealed - which is a shame, because there's one at another location I frequent that has a gaping hole in the side, turning it into an excellent reverb chamber. So, I wasn't sure if my recordings would pick up the tremendous reverb that results from hitting one. The sounds resulting from holding the mic near the end and striking it weren't all that impressive. I had better results micing the space between the two tanks, which are cylindrical and lie side by side. But the best sounds by far resulted from micing the 2" threaded pipe that leads into the tank (and lets the sound ouuut!).

Part of both tanks can be seen in this pic.
One downside to this location as a source of audio recordings is that it's situated next to an MDF plant, which produces a constant low rumble. Its frequency is such that when I scrub it from the audio it strips more of the lower frequencies away than is ideal. It's a constant battle to preserve as much of the original sound as possible while making it clean enough to be usable.

Wednesday, October 1, 2014

Digital Album: Radioatomic


At last, the album is complete. Releasing it in stages has been an interesting process, but I always intended it to be a cohesive work. Ladies and gentlemen, the first 'proper' album by The Manitou since 2008: Radioatomic.

Bandcamp player:

If you're a regular reader of this blog, you'll know that Radioatomic has been inspired by radioactivity and the Atomic Age. Production began in early 2013 and has taken over a year and a half to complete. That isn't to say it was my sole project during that time: two (as yet unreleased) soundtracks were tackled, and a handful of songs that didn't fit the theme are waiting in the wings for the follow-up.

The songs herein range from 'atmospheres' and experimental pieces to synthpop/electropop with a dark edge. They were created with a host of analogue and analogue-modelling synthesizers, virtual instruments, digital sampler software fed with 'found sounds' (field recordings, etc...), and a handful of drum machines and electronic toys (a track-by-track list of these devices can be found in the PDF booklet accompanying the release).

Track listing:
1. March Of The Rads
2. Electro Magnetic
3. Isotopes For All - Part 1
4. U235
5. Isotopes For All - Part 2
6. 96.1 MHz
7. Half Life
8. Global Warning
9. Nibiru
10. Radium Smile
11. Reactor Four
12. Atomic City
13. Cathode Ray
14. Fukushima Fifty
15. 96.2 MHz
16. A Robot In Every Home

These sixteen tracks all but fill an 80 minute CD, but the deluxe digital download on bandcamp includes seven bonus tracks: the single edits of five album tracks, an instrumental version of Half Life, and the electro mix of Atomic City. Thus every track released as part of the series of free singles is included in the package.

Also included is a 30 page .PDF booklet with liner notes, lyrics, and track-by-track artwork and instrument lists. For more detailed commentary on each track I suggest searching this blog for the keyword 'Radioatomic.'

The artists Atomic Shadow and Kraftwerk deserve special mention, as both heavily influenced this album. Specifically, it was #9 by Atomic Shadow that inspired me to browse the Prelinger Archive for public domain film reels, resulting in 'Isotopes For All' and 'Atomic City.' Kraftwerk have been an influence on my music from day one, but during production I realised that their 1975 album Radio-Activity had more than just its subject-matter in common with this project. If you haven't heard it I urge you to follow the link and do so.

Digital Single: A Robot In Every Home


The final free single from the Radioatomic project looks at the bright future promised by the advent of atomic energy that didn't quite live up to expectations. Sure, there were advances in many industries, but where are our personal jet packs, flying cars, and robot butlers? This was my inspiration for A Robot In Every Home.

Bandcamp player:

A Robot In Every Home [single edit] is drastically pruned down from the eight minute album version to serve up the essence of the track. It retains most of the intro, consisting of French horns, found sound, and a snippet of processed audio from a fun little film called 'Leave It To Roll-oh.' I was thinking of old RKO Radio Pictures black & white b-films, complete with a menacing mechanical man. Next come some synthesizer parts, the bulk of which were created with the Novation K-Station this time around. HS-60 is also present, and Gmedia M-Tron choir. The Korg Monotribe was used on the bridge, but that particular part was cut from this version.

Video:


Audio:

Like Radium Smile before it, this song started with the lyrics. Then came the melody as heard on the intro: something to set the tone for the Radioatomic album's 'big finale'. I spent some time last year sampling an electronic game called Parker Brothers' Merlin (see this post) and this seemed a perfect place to use the sounds. As well as the usual DR-550 tom-toms and synthesized percussion, there's the odd found sound in the mix, including a hand-clap with tight reverb recorded in the corner of a concrete foundation, and a pebble being dropped (into a drain pipe, if memory serves).

A Robot In Every Home [electro edit] rather than include the album version on the single I created this alternate mix, which omits the French horns and some of the samples. It has the same shortened bridge as the single edit.

There's currently no video for this track, but it's forthcoming. (updated 12/11/14). This release is twinned with the full Radioatomic album. Stay tuned to the next post for details!

Thursday, September 4, 2014

Digital Single: Radium Smile


My intention was to release the Radioatomic album tonight, to coincide with my birthday. But the booklet and liner notes aren't quite finished. Thankfully, the seventh single from the album was ready to go, so here it is: Radium Smile.


Radium Smile is inspired by the plight of the 'Radium Girls', who unwittingly poisoned themselves working for the Radium Dial Company in the early 1900's. Though the lyrics are tongue-in-cheek, I like to think this pays tribute to them in some small way. Musically, it's one of the poppiest from the new album (insasmuch as I write that sort of thing!). Unusually, the lyrics were written first. Once I had an idea of how I was going to sing it, I programmed a bass arpeggio on the K-Station. That synth provides most of the sounds and melodies. The Roland HS-60 makes a brief appearance on the chorus, and string chords from the Crumar Performer give what is a fairly bare-bones track a bit of meat. All percussion is either created from scratch or sourced from found sounds, with the exception of tom-toms from the Boss DR-550. Most of the sounds had already been added by the time the Korg MS-20 Mini arrived, but I managed to sneak it in on a bit of percussion before the mix-down. AnalogX SayIt provides the computer voice.

Audio:


Video:


I hope to release the album before the end of the month. Stay tuned!

Monday, July 7, 2014

Digital Single: Atomic City


Production on the Radioatomic album has slowed due to summer activities, but hasn't come to a standstill. I present the latest track intended for the album: Atomic City, plus a remix.


Atomic City was a last-minute addition to the album tracklist and slow to crystallize. For a long time it existed only as the treated film clip passages and atmospheric sound effects. It was only when the arpeggios and chorus melody came along that things fell into place. The bulk of the sounds heard here were realised on MS-20 Mini, marking its debut on the album material. The K-Station provides the arpeggios, HS-60 the main melody, and tom-toms were sequenced with the SamplePad as usual.

Video:

Atomic City [electro mix] came about when I sent the original track to my friend and collaborator Jimmy Aaron. He was curious to hear what it would sound like with a 4/4 beat behind it. The notion had also crossed my mind, so I gave it a shot. I turned it into a full-blown electropop track, and added some ideas that didn't make it into the original: such as the cut-up vocals towards the end. The new percussion elements were all created on MS-20 Mini. Also featured is the Lounge Lizard electric piano VST.

Video:

The treated monologue and film clips are taken from the film 'Magic Of The Atom: The Atomic City,' courtesy of the Prelinger Archives.

Saturday, April 19, 2014

Digital Single: Half Life


After a bit of a delay, here is the fifth free single leading up to the Radioatomic album: Half Life. It features a 'proper song' and a couple of experiments I like to call sonic atmospheres.

Bandcamp Player:


Half Life is perhaps my favourite song that I've written for the album. It was written in March of 2013 but not finished until this April. It started out with a basic loop made from a clock sample and a bass note from the Korg Monotribe. I called upon the K-Station for an arpeggio (and a few other sounds) you may recognise from other tracks, as I wanted to give the songs on this album a similar sound and style. The bulk of the lead sounds were made on the Roland HS-60. It wasn't long after I got it that I made this song, and I wanted to 'show it off' as it were. The Yamaha TG-33 also makes an appearance. It's a digital 'vector synth' designed for making evolving pads, but in this case I've just used its lovely bell sound. The drums are Alesis SR-16 samples which were initially programmed via keyboard but redone using the Alesis SamplePad to give them variable velocity and a few interesting frills here and there.

Audio:


Video:

March of the Rads is the earliest track I recorded for Radioatomic. It's essentially an aural journey into a radioactive wasteland. We hear the clicking of a geiger counter, getting faster as the radiation builds, the stark sounds of wind and other strange wiggly noises. I thought I was being clever, only to realise that Kraftwerk already did this in the 70's on the opening track to their album 'Radioactivity.' The geiger sound was realised on K-Station. If you apply a pitch modulation envelope to a sawtooth oscillator you can, with a bit of fiddling, slow the waveform waaaay down until it just becomes a click. Turning it slowly back up produced the backing track, which was then fed through a Danelectro Spring King (spring reverb pedal). HS-60 provides wind sounds and the weird wiggly radiation noise. Monotribe also makes a brief appearance and you can hear some radio frequency sounds towards the end.

Video: (coming soon)

Global Warning while doing research for the album I happened upon this youtube clip, filmed inside Sellafield THORP. At 3:50 you can hear the criticality alarm which sounds perpetually inside the building. I found the whole idea rather creepy and thought it would be a cool experiment to replicate the ambience using synthesizers. The blips were made on the Monotribe through the Spring King. HS-60 and K-Station each provide a layer of filtered noise to emulate the background hum of the industrial building.
 
Video:

Friday, March 14, 2014

Tech Notes: Mastering

A friend of mine was asking me about mastering recently, specifically whether I master my tracks or not, so I explained my methods to him. It occurred to me it might make an interesting blog post.

What is mastering? Essentially it's the final step in preparing audio for the listener's ears. Generally it means taking a finished song and running it through EQ and compression so that it sounds big and beefy like you expect a song to sound on the radio. Now, I have a huge problem with how popular music is mastered these days, so the mastering I apply to my music is minimal at best. I make sure the EQ is how I want it at the mixing stage, and apply only enough compression to the final mixdown to ensure that the overall loudness of each track is roughly the same. No fancy squeezing of the bass, expanding of the mid-range, or sharpening of the high end that could give you papercuts.

When a multi-track mix is finished, the first thing I do is play it back with the VU meter running, so that I can see whether or not the output is clipping. I touched on clipping in another post, but essentially it means audio is going 'into the red' and being cut off (or 'clipped') from the output stereo audio file. If this is happening, the VU meter will tell me exactly how much audio is going above the cutoff point, and I can drag the faders down to compensate. The end result is a clean file with all the audio information present, but a much lower volume than intended. I refer to this as the 'pre-master.'

The pre-master is then loaded into my audio editing program of choice: Sound Forge XP. The first thing I'll do is open the Normalize dialogue and run a scan for two things: the maximum peak level of the audio, and the RMS (overall loudness). If I've done my job correctly, the peak level will be somewhere below 0db (maximum). The RMS will vary depending on how much I've had to lower the volume of the track. It's generally somewhere in the region of -20 to -15db.

Sound Forge: the normalize dialogue box. Note peak level and RMS.
This is the waveform representation of a pre-master from a forthcoming e.p. Note the peaks are not touching the edges of the box. This is good - it means it isn't clipping.

Waveform: pre-master.
The RMS isn't always a reliable way of determining how loud I want the finished track to sound. If a song has no drums, for example, the RMS will come out wildly different compared to one that has. From research and trial-and-error I've determined that an RMS of -15db is a comfortable level for my music. Sometimes this varies from track to track by a factor of up to 5db. Ultimately I rely on my ears for the final judgement.

In order to bump the volume back up to where it should be, without the audio clipping, a compressor is required. This is a bit of software (or hardware) that determines which parts of the audio are clipping when you turn it up, and smooths them out instead of cutting them off drastically like a pair of scissors. The result is much more pleasing to the ear, but care must still be taken not to use too much compression, otherwise your audio will end up sounding like a Ricky Martin record (gasp!), and the waveform will look like a solid blue line, instead of a nice centipede shape.

Sound Forge has several compressor plugins, and they can be puzzling to work with if you don't know the first thing about them. I rely on the tried and true Wave Hammer compressor. Here's a picture of the dialogue box and the preset I use, called 'Master for 16-bit,' which takes all the guesswork out of it.

Wave Hammer: Master for 16-bit.
Inasmuch as I understand it, the first slider is the threshold, or the part of the waveform the compressor is going to lift up by its boot-strings. The second slider is how much attenuation, or squashing, of the peaks is going to occcur. The third is for the overall volume you wish to apply to the track beyond initial compression. If, for example, I've had to pull the volume down severely on the pre-master, I'll experiment with the output gain until I get back at least the amount of volume I took away in the first place.

Waveform: mastered version.

Here is the mastered waveform. You can see it's considerably fatter than the original (by a factor of 5db to be exact), yet you can still see the gaps between peaks: the mark of a successful operation!

Once this is done and I'm happy with the final result, I normalize to 98% (this is just a personal preference, and brings any peaks hitting -0db down to -0.02), and apply fade-ins or -outs if needed. I might also add silence to the end of the track if I think it leads into the next one too soon. Oftentimes I'll have to make adjustments or master a track from scratch if I've got something wrong in the mix, so I've taken to making notes of just how much compression I apply and any other edits I make after the fact.

And there you have it: how a Manitou record is prepared for consumption without making anyone's ears bleed or speakers explode.

Wednesday, February 26, 2014

The Manitou featured on Caliper Music

My single Cathode Ray has been featured on Caliper Music: an experimental music blog. I recommend checking them out if you're into experimental music and 'out there' sounds.

Saturday, February 22, 2014

Reviews: Reactor Four & Cathode Ray

Mark Barton of The Sunday Experience has reviewed my two most-recent releases. Here's what he had to say:

Reactor Four
Cathode Ray
Those of you loving your electronics spared in minimalism like it was 1979 and steered in a sinister off set funky iciness might want to stay with the Manitou a little while longer for the follow up to ‘reactor four’ – and by a quick head count the fourth in the singles series is entitled ‘Cathode Ray’. This un plugs directly into Human League Mk1’s sound space more specifically having us reaching for our copy of ’reproduction’ in order to sample the dark delights of ‘circus of death’.

My promo video for Cathode Ray has also been featured on Matrixsynth blog, of which I've long been a fan. If you're into synthesizers and you haven't paid it a visit, I urge you to do so.

Friday, February 21, 2014

Digital Single: Cathode Ray


Fourth in my series of free singles is Cathode Ray / U235. These both lean towards the experimental, so they were a lot of fun to put together. There's nothing like unleashing your 'mad scientist' side in the studio!

Bandcamp player:

Cathode Ray opens with a march-like rhythm created from snippets of a sample & hold patch on the Korg Monotribe. The Monotribe also provides a recurring bleepy filter sequence. A bassline, drone, and some percussion sounds recorded from a Toshiba radio form the backbone of the track. The Alesis SamplePad was used to sequence some Speak & Spell percussion and tom-toms. Novation K-Station adds some extra percussive sounds. I manipulated my voice with the Marantz PMD201 tape recorder to create the spoken word part. A very nice VST called Lounge Lizard provides the electric piano.

I should point out that the TV featured in the artwork is exactly as I found it. No TV's were harmed (by me) in the making of this e.p.!

Audio:

Video:

I did something a little different with the video this time. It's shot entirely with a 40mm macro lens and features some of the instruments and devices I used to make the music. My tin robot 'Mini Radiocon,' which you might recognise from the cover of 'Let's Build Mecha!', also makes an appearance.

U235 was the first track I made for the new album project, and my first experiment with the Korg Monotribe. Once I had a patch and a sequence programmed, I recorded several live improvisations, cut them into chunks, and assembled them into a track. I then created various percussion sounds on Roland HS-60, TAL U-NO-LX, and K-Station, and added in a snare from the Yamaha MR-10. HS-60 provides some other synth sounds, more Monotribe was overdubbed, and K-Station and Yamaha CS01 also provide some melodies. Electric guitar can be heard on the ambient sections (backwards). My voice was once again pitch-shifted with the Marantz PMD201.

The title refers to the only fissionable isotope of uranium to occur in nature. In the film A Is For Atom, which I sampled for Isotopes For All, U235 is represented by a frenetic cartoon character. The bouncy arpeggio reminded me of that.

Audio:

Video:

Tuesday, February 18, 2014

New Equipment: Korg MS-20 Mini


The Korg MS-20 was produced from 1978-83 and has since become something of a legendary synthesizer. The brand new (as of this writing) MS-20 Mini is a complete recreation in a slightly smaller housing, with the addition of very simple MIDI implementation (it has MIDI In to allow sequencing, nothing more). The basics: it is analog, monophonic; has two oscillators, one LFO, and two filters (high & low pass). It's also semi-modular in that certain functions can be re-wired or patched-in via the patch panel on the right-hand side of the synth.


In 2002 I bought my first proper synthesizer: the Novation K-Station. It's a fantastic machine but at the time I found it exceedingly complex. While it has a wealth of hands-on control, a great deal of its parameters are hidden in the menu system. As I've come to learn its ins-and-outs, it's proven its versatility and I still use it as my main instrument. But circa 2005 I wanted to get my hands on something simpler in order to get to grips with basic synthesis.

The K-Station, a true workhorse.
This led to a search for such an instrument, and among the contenders was the MS-20. Unfortunately it was long out of production, and I'd missed out on the 'great analog purge' of the late '80s early '90s, when analog gear was practically being thrown away in favour of digital. By this time analog was back in vogue and the MS-20 was fetching upwards of $2000 USD. So, after much consideration I settled for a Yamaha CS-5. It only had one oscillator, but its design was such that it had oodles of character. It was simple and easy to use, and it helped me get to grips with synthesis and the K-Station. Being of a vintage, and I suspect mistreated by its former owner, the CS-5 failed within a short time. The handful of songs I made with it are among my favourites, and for a long time there was a void in the studio that couldn't be filled.

Alas, poor Yorick... the ill-fated CS5.
When the MS-20 Mini was announced I was understandably excited, and I pre-ordered it the first chance I got. The demand for it was such that it took 11 months to arrive. It has not only filled the gap left by the CS-5 in my sound palette, but expanded it to undreamt of horizons. You will no doubt be hearing a lot from it in the coming months.

The day of its arrival. The postlady dropped it and ran away (I kid ye not).

Sound exploration in progress!

Saturday, January 25, 2014

Promo Videos: The Mechanicals (Part 2)

I took a short break from my single releases to illustrate a couple of tracks from 2012's 'The Mechanicals' e.p. I've had some of the video footage 'in the can' since I completed the release but never got around to editing it. I'm glad I waited, because I ended up shooting some extra footage that greatly improved the visuals.

First up, here's The Mechanicals (Part 2). I decided to go with monochrome for this one, to reflect the mood of the piece.

Video:

Secondly, The Mechanicals (Part 2) [End Of The World Remix], which was a collaboration with my friend Jimmy 'Jamz' Aaron. Since the track has a lot more energy to it and uses a lot of the same footage, I chose to keep it in colour.

Video:

For those of you that are interested in such things, the mechanical devices seen in these videos are a hand-cranked rolling mill, a vintage Remington 12 typewriter (which can be seen in this post), and a vintage electric sewing machine (the make and model of which escapes me at the moment). They were filmed with a Nikon D7000 (as are all my videos of late) with an 18-55mm kit lens and a 40mm macro.

Thanks to: Jimmy for the collaboration, my dad for the use of the rolling mill, and my uncle for the use of the typewriter.

You can, of course, still purchase The Mechanicals e.p. via my bandcamp page, and read all about it in this post.

Saturday, January 11, 2014

Digital Single: Reactor Four



This month's free single is a double-bill inspired by nuclear disasters: Reactor Four (Chernobyl) and Fukushima Fifty (Fukushima Daiichi). Both of these horrendous events continue to threaten life on this planet and will do so far into the future. My music is often inspired by grim subject matter, and writing about the real world instead of fiction for a change is my own small way of creating awareness.

Bandcamp Player:

Reactor Four is built on a moody percussion loop created by a rhythm box manufactured in the 60s: the Univox SR-55. Two instances of the loop were pitch-shifted, fed through a software emulation of the famous Moog ladder filter (to enhance the noise that sounds like crickets), compressed, and then fed through two stereo delays. Over this I added an odd pulsing arpeggio and bassline (K-Station) various synthesized percussions (KS & HS-60), and ye-olde strings in the form of GMedia M-Tron (a Mellotron emulation). HS-60 provides further synth sounds, and the Korg Monotribe is brought in on the outro to supply some acid basslines and theremin-like pitch-ribbon improvisation. Vocoding was done as usual through the K-Station. The 'big 80's drums' were originally done via MIDI keyboard, but I re-did them using the Alesis SamplePad once I discovered what a difference variable velocity (aka. loudness) made. The drum samples themselves were taken from the Alesis SR-16.

Video:

Audio:

Fukushima Fifty was originally envisioned as an addendum to Reactor Four, hence it has the same tempo. The music went in a different direction so it became a track in its own right. A rhythm loop from the Casio MT-100 provides the backbone. I also used a tone from that quaint little keyboard during the refrain. The vocoder that opens the track was slowed down to half-speed, because I liked the imperfections it added. K-Station, HS-60, and Monotribe were also used. Crumar Performer provides the strings this time, and electric guitar adds a touch of menace to the outro. It was recorded through the distortion effect on the Roland SP-404. I honestly can't remember if the soaring 'Vox Humana' synths at the end are HS-60 or Alpha-Juno, but I think it's the former. Percussion-wise, there's some Speak & Spell, but the bulk of it is synthesized from scratch.

Video:

Audio: