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I'm just wondering, what would be the attributes of "bad" audio be?<div><br></div><div>This is a good question. Nick answered re microphones. I'd like to touch on this with particular emphasis on digital recording and phones since that's my thing.</div><div><br></div><div>Aside from microphones, there's two subsystems that affect audio quality. The first is the audio amp (pre-amp) between the microphone and the ADC (analogue-to-digital converter). This has been easy to get right for decades now, so this is rare. Bad implementations will be noisy (hiss when recording nothing) or have some constant pitch noise (mostly laptops) due to interference or fans. I've seen this on cheap mobile phones and particularly on laptops (easily cured by using an external USB microphone). I've also seen very good audio on cheap mobile phones. Mid to high level phones are generally excellent. The most significant drawback of mobile phones is that they are mono but there's solutions to that, see below. </div><div><br></div><div>The second subsystem is whatever encodes the raw output of the ADC to the data format that's saved. The biggest impact is audio compression. Obviously you can sidestep this by avoiding compression. Audio compression has a poor reputation stemming from poor experiences with the (ancient) MP3 format. Bottom line, it's easier to just turn off and know it wont be a problem.</div><div><br></div><div>Other sources of 'bad audio' can be somewhat more dynamic. One of the most common is audio clipping. This is an operator problem that often stems from outdated practice. In the days of analogue recording, best practice was to ensure the audio level is at the top end of the range to maximize SNR (signal-to-noise ratio). 16-bit digital recording has a *massive* SNR, greater than 90dB in many cases, and unlike tape, if you exceed it, the effect is catastrophic, with obnoxious clicks and crackles that will not only destroy the audio for computational acoustic analysis, but will even make it unpleasant and difficult to comprehend.</div><div>The solution is obviously to turn down the gain. You only need to see a couple of 'pips' or a needle moving a bit, to be sure your audio is working. You can turn it up with processing later on, with no ill effects.<br></div><div><br></div><div>Another form of bad audio stems from dynamic range compression and/or the related automatic gain control. TLDR; use manual gain, or turn automatic gain control off if you can, or at least be aware of when it might be a problem.</div><div><br></div><div>Longer explanation: The pre-amp (hardware) I mentioned earlier is controlled by software. The software tries to obtain a sufficiently loud recording based on the conditions. So if you're quiet, it ramps the gain up, if you're loud, it ramps it down. There's actually a really fast method to cope with transients (dynamic range compression), and a slower method to set the general gain level (AGC). Mobile phone AGC is particularly aggressive since it has to cope with recording everything from quiet ambient audio, up to yelling into the microphone at close range! AGC can be an issue with dedicated recorders. Consider this. You're recording a participant in a noisy village with a mobile phone placed closed to them. The cultural norm is to wait some time before answering a question. The problem is that the phone ramps up the gain and all you can hear is the pots and pans from the nearby kitchen. Then when the participant starts speaking, the audio clips (is distorted) for a moment, before clearing up and the pots and pans recede to the background. That's what AGC might look like in a typical environment. The solution is to turn AGC off, and do a quick sound check with the participant speaking. If ambient noise is remotely an issue then close mic'ing gives you a better result than a directional microphone. Hence why you see lapels on reporters when they are standing in front of some unfolding disaster on cable news. </div><div><br></div><div>So while I'm here, some common issues/misconceptions of audio recording. Sorry for those that this is obvious.</div><div><br></div><div>In my view the majority of digital recording devices, except for laptops and cheap mobile phones, is more than up to the challenge, and any noise or distortion is so small so as to be negligible. The largest source of unwanted signal (noise) stems from microphone strategy. This is also the best way to approach evaluating recording devices in general. When you buy a dedicated recorder, you aren't getting magical capability to produce better audio. What you do get is a robust unit with good battery life, easy to reach audio controls, good input options (like maybe XLR) and some kind of basic functional directional microphone. </div><div><br></div><div>These are significant but they are achievable in other ways. *Most* third party shotgun microphones are better than what you get on a Zoom. Ergo, plug that one into the device of your choosing and get better audio than a zoom. That doesn't negate the other reasons for a Zoom, or other, record as above.</div><div><br></div><div>Next, there's a whole load of mythology in this genre around bit depth and sample rate. Bottom line, but if you are recording voice, you are not doing yourself any favours by using a sample rate more than you need. It's not like camera megapixels, you can't scale down and get a better result. 24-bit is pointless. 96/192 or whatever Khz is harmful audiophile snake oil* used to put bigger numbers on the box for marketing purposes. That's why Steven said he's recording at 16KHz. </div><div><br></div><div>Returning to the parent topic, I suggest a couple of recording options for either end of the budget.</div><div><br></div><div>1. The 'ghetto' lapel. Using a mobile phone in a lanyard or in a top pocket. </div><div><br></div><div>This is basically radio lapels on a budget. For best results, use a recorder app that allows you to manually set the gain. Cleverly you can deploy this to several people at the same time and sync them up, giving you as many audio channels as you want. David Nathan has drawn attention to the fact that stereo audio ought to be considered the minimum (audio positions is a kind of metadata).</div><div><br></div><div>2. Use of a camera with an external microphone. </div><div><br></div><div>Cameras are rugged reliable devices with good tripod mounts. Ideal for capturing video and audio. A lot of what's good about dedicated audio recorders (rugged, battery life, big memory capacity) also applies to cameras.</div><div><br></div><div>You can turn down the video quality to maximize record length. The video will still be outstanding. Audio input is sadly a feature you have to hunt for, and you wont be getting XLRs, but audio input can be found on cheaper cameras, for example the Panasonic FZ1000 (there's a newer one now) which has been a workhorse of mine. It soldiered on while everything else broke and failed. It has proper gain controls and on-screen audio level indication. As a far-mic solution, you need a directional microphone. There are many shotgun microphones that will fit the flash shoe at the top of a camera. I bought a cheap one off eBay and it's outstanding. Camera audio will be compressed, but it will be 48KHz AAC usually, more than sufficient. There's a step required to extract the audio if you need stand alone audio files, which may be a factor.</div><div><br></div><div>Sorry if I strayed the topic a bit :)</div><div><br></div><div>* <a href="https://people.xiph.org/~xiphmont/demo/neil-young.html">https://people.xiph.org/~xiphmont/demo/neil-young.html</a></div></div></div><br><div class="gmail_quote"><div dir="ltr">On Tue, 28 Aug 2018 at 14:03, Hugh Paterson <<a href="mailto:hugh_paterson@sil.org">hugh_paterson@sil.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Nick Williams,<div><br></div><div>I'm just wondering, what would be the attributes of "bad" audio be? I'm never read a technology review of a "bad" piece of equipment in LD&C.</div><div><br></div><div>all the best,</div><div>- Hugh</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Aug 27, 2018 at 7:54 PM, nick williams <span dir="ltr"><<a href="mailto:n.jay.williams@gmail.com" target="_blank">n.jay.williams@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div dir="auto">Zoom Q8 with a shotgun microphone (if you can buy fewer units and share or up your budget slightly). you might be able to get a used one for under $300. i know it is a bit over your budget, but they are very good and video is the way to go unless people are for some reason uncomfortable with video. the audio is quite good too. it has xlr inputs as well and possibility of four channels total. </div></div><div class="m_-5733475846971076195HOEnZb"><div class="m_-5733475846971076195h5"><div><br><div class="gmail_quote"><div dir="ltr">On Fri, Aug 24, 2018 at 8:17 PM Steven Bird <<a href="mailto:stevenbird1@gmail.com" target="_blank">stevenbird1@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi Heather,<div><br></div><div>Plenty of voice recorders support uncompressed recording. I've been using Smart Recorder, Parrot, and Hi-Q, all of which record in RIFF (=wav) format. The first two also support sample rate selection, and I choose 16kHz 16 bit mono.</div><div><br></div><div>That's 32kB/s or ~0.1GB/h. For A$40 you can fit out your phone with a 64GB micro SD card and record for ~600 hours.</div><div><br></div><div>-Steven</div><div><br></div><div><div>--</div><div><span class="m_-5733475846971076195m_-6311349045910651017m_-7597522472648481950gmail-il">Steven</span> <span class="m_-5733475846971076195m_-6311349045910651017m_-7597522472648481950gmail-il">Bird</span> <a href="http://stevenbird.net/" target="_blank">http://stevenbird.net</a></div><div>Professor, College of Indigenous Futures, Arts and Society, <span class="m_-5733475846971076195m_-6311349045910651017m_-7597522472648481950gmail-il">Charles</span> <span class="m_-5733475846971076195m_-6311349045910651017m_-7597522472648481950gmail-il">Darwin</span> <span class="m_-5733475846971076195m_-6311349045910651017m_-7597522472648481950gmail-il">University</span></div><div>Linguist, <span class="m_-5733475846971076195m_-6311349045910651017m_-7597522472648481950gmail-il">Nawarddeken</span> Academy, Kabulwarnamyo Community, Northern Territory<br></div><div>Research Scientist, International Computer Science Institute, <span class="m_-5733475846971076195m_-6311349045910651017m_-7597522472648481950gmail-il">University</span> of California <span class="m_-5733475846971076195m_-6311349045910651017m_-7597522472648481950gmail-il">Berkeley</span></div></div></div><div dir="ltr"><div dir="ltr"><br></div><div><br><div class="gmail_quote"><div dir="ltr">On Tue, 21 Aug 2018 at 21:10, Julia Sallabank <<a href="mailto:js72@soas.ac.uk" target="_blank">js72@soas.ac.uk</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>Dear Heather</div><div><br></div><div>I've used the Zoom H2N with community members, together with very simplified instructions, but they still had problems with it. The easiest thing would be to use the record or video function on mobile phones. I know there are other communities using mobile phones for language documentation, and phones also have the advantage of being familiar and thus intruding less on the conversation. I know that the recording quality is mp3 not .wav, but for language learning and MAP purposes that should not be a problem. I would also recommend not recording at all for the first meetings, to put people at their ease.</div><div><br></div><div>Good luck!</div><div><br></div><div>Julia<br></div><div><br></div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On 18 August 2018 at 23:38, Heather souter <span dir="ltr"><<a href="mailto:hsouter@gmail.com" target="_blank">hsouter@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Taanshi! Hello!<br>
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Heather Souter d-ishinikaashon. En Michif Camperville, Manitoba, Canada oschi niya. Daweeyiteen lii zavii. Mahti wiichihin...<br>
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My name is Heather Souter. I am a Michif from Camperville, Manitoba, Canada. I need some advice. Please help...<br>
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Looking for some collective wisdom here. I need a range of ideas for the lowest tech to the highest (and a few in between?!) recording devices to use with a group of community-based Indigenous language learners of widely ranging digital skill levels? The budget is CA$ 160..?<br>
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Zoom H1 and Zoom H1n have been suggested. Any other suggestions on the lower and slightly higher tech sides? Something my non-tech savy elderly auntie could use and then maybe something with a XLR input?<br>
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It is for an upcoming MAP pilot project..<br>
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Kihchi-marsii. Thank- you!<br>
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Eekoshi pitamaa. That’s it for now.<br>
<span class="m_-5733475846971076195m_-6311349045910651017m_-7597522472648481950m_-979135015502238540HOEnZb"><font color="#888888"><br>
Heather<br>
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</font></span></blockquote></div><br><br clear="all"><br>-- <br><div class="m_-5733475846971076195m_-6311349045910651017m_-7597522472648481950m_-979135015502238540gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div>Dr. Julia Sallabank<br>Reader in Language Policy and Revitalisation, School of Languages, Cultures and Linguistics<br>Associate Director for Learning and Teaching Quality (PGT)<br>SOAS, University of London, <br>London WC1H 0XG, UK<br><br>Tel. +44 (0)20 7898 4326<br></div></div></div></div></div>
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</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="m_-5733475846971076195gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><b>Hugh Paterson III<i> </i></b><span style="color:rgb(153,153,153)"><i></i>Innovation Analyst</span></div><div><i><span style="color:rgb(153,153,153)">Innovation Development & Experimentation</span></i>, <b>SIL International</b><br></div><div> </div><div><b>Web</b>: <span style="color:rgb(153,153,153)"><a href="http://hughandbecky.us/Hugh-CV/" target="_blank">Contact & CV</a></span> </div><div><br><br></div></div></div></div></div></div></div></div>
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</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature">Regards,<br><br>Mat Bettinson<br><br></div>