Audio hardware: Difference between revisions
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== Network/Hardware Ideas == |
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== Microphone == |
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===Sound Codec=== |
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A built in Microphone would be usefull if dirt and echo/feedback could be controlled. If you have a microphone and speakers included with these laptops then then if you include a small peice of software they can be used as telephones or walkitalkies -- like an instant message local channel that is as easy to use as a CB radio. If the hardware looked like a radio, the oporator could use it before they learend how to use the computer. |
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The [[Hardware specification]] page says the Audio Codec is an [http://www.analog.com/en/prod/0%2C2877%2CAD1888%2C00.html Analog Devices AD1888], AC97-compatible audio codec. |
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===The provenance laptop=== |
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The paper - 'The One Laptop per Child (OLPC) Audio Subystem' by Jaya (Alsa) provides useful information on the audio subsystem. The link is - |
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An issue about the provenance of the particular copy of the (yet-to-be) published program obtained for running by a child on a laptop has been written about in the http://wiki.laptop.org/index.php/Application_Program:_Test_of_ability_with_arithmetic#Verifying_the_program section of the |
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[http://www.kgw.tu-berlin.de/~lac2007/papers/lac07_kumar.pdf The OLPC Audio Subsystem] |
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http://wiki.laptop.org/index.php/Application_Program:_Test_of_ability_with_arithmetic page. |
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--[[User:Arjunsarwal|Arjunsarwal]] |
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===Microphone Sensor Input=== |
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A possible solution has been suggested. This is termed a provenance laptop therein. It is different from the server version which is suggested above. |
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The microphone input can be used to measure voltage or (using the Microphone bias voltage) resistance. This should enable us to use this as a form of sensor input with the audio analog to digital converter converting the sensor signal to a signal that can be displayed on the screen or logged by the computer. More info is required on the use of the codec in this mode. |
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In view of the fact that the provenance issue is likely to be important for many programs, not just for the application program in relation to which the issue was raised, the idea of the provenance laptop is copied to this Hardware Ideas page. |
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* max voltage that can be withstood safely by the mic input |
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Would it be possible for there to be a special, variant, version of the laptop, say moulded in a colour different from the laptops issued to the children, which is read-only of files, with files being obtainable only over the internet and then only from one particular webspace? This special, variant, version is herein termed a "provenance laptop". The system software for such a provenance laptop could be in read-only memory. Thus, if the idea is feasible, a child could obtain files from a provenance laptop with confidence. The provenance laptop might, from time to time, need to be transported several miles to a place where files could be obtained from the internet. However, the availability of a provenance laptop facility in a rural school where there is no direct connection to the internet could be a good second best to having a direct internet connection. The provenance laptop could be used to select which files are obtained from the one particular webspace. The one particular webspace could either be a special webspace run by the government of the country where the laptop is deployed or a special webspace of the OLPC project run by the OLPC management under secure conditions, depending upon the policy choice of the government of the particular country. |
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* Voltage corresponding to AD converter full scale. |
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* Bias voltage output (open circuit) |
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* Bias voltage output (short circuit) |
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* Frequency range of mic input |
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* anything else? |
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===Uses of making measurement using the analog input port on the laptop=== |
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=== Broadcast and Satellite === |
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This section is useful for compiling a list of important and interesting uses for sampling analog input voltages using the analog input port of the laptop.It would also help in determining the end requirements of voltage range that would be required to be supported int he laptop at input. |
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See [[Hardware Ideas - Broadcasting]] |
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Uses and their electrical requirements (Voltage range, bandwidth, Bias) |
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===Motorcycle Net=== |
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There are already people using motorcycle delivery services to carry email from village to village in Cambodia's [[Motoman]] project. This type of networking is likely to grow once there are large numbers of wireless capable laptops in place. They either exchange info wirelessly with the motorcycle, or, more likely, a teacher runs a village base station that can collect messages all week, then do a quick upload and download while the motorcycle driver is dealing with the paper mail. Bulk data transfers would be on CD or DVD since USB drives are readily available. The villagers will quickly learn how a single USB-CD drive can multiply the usefulness of those laptops 100-fold. |
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1. Checking the voltage of an AA/AAA/C/D type cells- Should be able to sample DC in the range 0-1.5V |
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===Radio distribution of content=== |
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2. Checking the voltage of a PP3(9V) type cell - Should be able to sample DC in the range 0-9V |
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The basic suggestion is to adapt existing technology for broadcasting data over the radio and use it as a widespread distribution tool for content to the laptops or, more likely, to some central site in the village. Once in the village it can be distributed further using the built-in wi-fi of the OLPCs. The radio would presumably be similar to existing USB DVB-T receivers available in Europe to receive digital television broadcasts. This could be done in one of two ways. One way is to fill up a shared library in each village. The other way is to constantly repeat the same documents so that villages do not need to have large storage capability. |
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3. Checking the voltage of a car battery - Should be able to sample DC in the range 0-15V |
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[[MHP_to_laptop_interface_possibility|MHP]] has been suggested as a possible source of this technology. |
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4. Interfacing an LDR/photo voltaic cell/Temperature sensor - Bias voltage required . Voltage range = |
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== Hardware/Accessory Ideas == |
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5. Robotics applications - The interface that is usually provided with commercial |
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=== Keyboard === |
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modules such as distance ranging modules is a 0-5V digital output. If the output voltage interface is RS232 type then voltage sampling requirements extend upto -12V - +12V. But then the XO has a serial port ? (Yes, but the connector is not exposed. --[[User:Walter|Walter]] 20:58, 24 June 2007 (EDT)) |
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--[[User:Arjunsarwal|Arjunsarwal]] |
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Moved -- see [[Hardware Ideas - The Keyboard]] |
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--[[User:Doug|dlarue]] 07:02, 15 January 2008 (PST) |
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=== Green Hardware === |
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Some Ideas from [http://www.worldchanging.com/archives/003881.html WorldChanging]: |
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"...We typically discuss organic polymer electronics (OPE) as a feature of the fabrication future, but the clean leapfrog application is important, too. The production of OPE is much cleaner than traditional electronics, and the materials themselves contain few if any heavy metals. Recent OPE developments include a microprocessor able to run at around 100MHz (far slower than today's fastest laptops, but easily fast enough for the kinds of basic information and communication tasks described for the OLPC project), a variety of slower circuit and sub-processor plastics, an organic polymer battery and even a colorful, fast flat-panel display. Even the solar panels often suggested as an add-on for the hundred dollar laptop could be made with organic polymer materials." |
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=== Power and Batteries === |
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When you look at military PDAs,they are powered by fuel cells that aren't so available in these countries and are not in the price range being considered. We have to do something with the options available. |
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=== Make your own batteries === |
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Is it feasible for the kids to make their own batteries to power the OLPC? This would be a fantastic science project if it is possible. If potato and lemon powered clocks are possible, this should be too. |
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==== Batt types and charges ==== |
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If you are constantly recharging the battery all the time this will greatly decrease the life of the battery. |
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NiMH batteries do not suffer from "memory effect", in fact NiCd batteries don't normally either. But, both types do suffer from voltage depression; when they are fresh and new they give a voltage of 1.2v per cell so 8 cells will give 9.6v, a useful amount. But if the cell is over charged or just always on trickle charge the cell voltage soon drops to just about one volt per cell; just 8v total, the equlivent of removing an entire cell. The interesting thing is voltage depression does NOT effect the total capacity of the battery. I have NiMH and NiCd that are completely depressed (hmmm) but they still do the job as well as they did when new. |
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The problem with this is the discharge graph [http://www.uniross.com/UK/industrial/Product%5Ccharacteristics/010302]. You will notice that it's mostly flat so some designers take the 1.2v as gospel and design thier electronics to shutdown at 1.1v. If the battery is depressed by 0.2v this line comes in at about 10%..15% of the way into the capacity so you only get 10%..15% of your two and a bit hours of charge ... 20 minutes... [[User:62.252.0.11|62.252.0.11]] 15:42, 17 March 2006 (EST) |
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i heard that nicd and nimh batteries have some fake memory effect: |
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it was said that they were afected by another redox transformation than the normal,when they keep staying pluged on after having fully recharged the batteries: |
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this redox transformation will divide the battery in 2 and have a part with the normal voltage and another part with an inferior voltage |
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usualy that caan be easely detected because there is a voltage jump and so they needed to be full discharged with a resistor in order to get back their capacity but i don't remember the formula for calculating the value of the resistor |
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[[User:213.189.165.28|213.189.165.28]] 19:48, 4 April 2006 (EDT) |
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=== Microphone data input === |
=== Microphone data input === |
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The microphone input jack can double as a dataport for some class of devices (when supporting a "DC-coupled" input mode), but a more general-purpose USB analog to digital device would be a great peripheral for the laptop. --[[User:Walter|Walter]] |
The microphone input jack can double as a dataport for some class of devices (when supporting a "DC-coupled" input mode), but a more general-purpose [[USB peripherals|USB analog to digital]] device would be a great peripheral for the laptop. --[[User:Walter|Walter]] |
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=== AD/DA & "Parallel" interfaces === |
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:::: Precisely for these types of ideas the computer needs some sort of basic A/D, D/A and suitably protected bi-directional "parallel" type interfaces. These need to be built-in so their use doessn't add wire spaghetti, cables/conversion boxes don't get lost, is "fumble free" and always available. In short, it must be '''simple''', '''empowering''' and an '''idea generating catalyst'''. [[User:Larry Pfeffer |L Pfeffer]] March 20, 2006 |
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* Or perhaps these miscellaneous fun things should all be available on a USB interface. It would keep it very expandaple, yet low base cost. USB devices keep getting less expensive to develop. --imajeff |
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=== Serial Port?? === |
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I know it can be done thru USB emulators... but serial ports are simple and easy to use. If someone wants to make some electronic project, or using old hardware (mouse, or serial comunications devices), it could be useful to have one. |
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it's just an idea, but I started making my first hardware projects with this, and even today is cheaper (at least here in Argentina) and easy to make serial ports working hardware (rather than buying PICs and programming them). |
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And still many hardware has serial ports (networking devices for example). |
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[[User:Gandolfi|Gandolfi]] |
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:::: Serial ports are NOT robust, at least nine tiny little pins that it's very easy to bend or break, not a good idea. Perhaps with a more robust connector, though IME the parallel port was more useful for electronics projects. [[User:62.252.0.11|62.252.0.11]] 16:02, 17 March 2006 (EST) |
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:::: The photos from the developer boards show an external RS232 level shifter circuit attached (to some GPIO pins?). Legacy serial/parallel ports are nice for experimenting, there's IMHO no need for this for a laptop which is targeted at 6-12yo childs. |
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:: Not to mention the fact that there IS NO OLD HARDWARE in these 3rd world villages. It would be far better to have an external power plug with circuit breaker switch so that people could use the old bananas they have laying around TO MAKE BATTERIES!!! The kids will be motivated to find a way to pedal less so lets help them learn some science. |
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=== Additional Architectural Elements === |
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See [[Hardware Ideas - Additional Architectural Elements]] |
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=== ORP 12 === |
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Moved to [[Hardware Ideas - Fun Things]]. |
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=== Including built-in streaming from e.g. teacher to students === |
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Would the current architecture, including display design/resolution/framerate etc. allow for this in principle? |
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On the software side, how about some peer-to-peer streaming stuff; one CD or DVD drive/player per school class, and groups of kids watching a (same) movie on several laptops? This is possible with e.g. VLC - but could be built-in, preconfigured/high-lighted and very simple - thingie pops up saying "A neighboring laptop has started streaming video, would you like to watch?" - done. |
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The hardware exists off the shelve... but will they all work out of the box? Drivers? Can player software be included in the "default" software? If not a full-blown "certification" program, at least at page (on this Wiki!) with "external devices known to work" (or if not, instructions on how to get them to work will probably be needed. |
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[[User:Vorburger|Vorburger]] |
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== |
== Old thoughts == |
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A built in Microphone would be usefully if dirt and echo/feedback could be controlled. If you have a microphone and speakers included with these laptops then then if you include a small piece of software they can be used as telephones or walkie talkies -- like an instant message local channel that is as easy to use as a CB radio. If the hardware looked like a radio, the operator could use it before they learned how to use the computer. |
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<b>Is anyone willing to consider a more immediately available, dumb-terminal version of the device which would have nothing more than a touchscreen and an ethernet port?</b> |
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These are ideas related to both audio input and output. Please review the [[hardware specification]] to see what is already included. Some audio-related ideas are also dealt with in the [[Radio and Broadcast]] page. |
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:: I WANT! A small silent X-Terminal/Media player connected by WiFi/Ethernet to a big box will be a killer app for the Linux based home or office network. Doesn't work with Windows, Microsoft see to that. This is a different spec to the OLPC though, you'd want POE or better yet network over 6-pin firewire (firewire is designed to supply lots of power) you'd probably want a 1024x768 full colour screen and perhaps more memory. This is the $2000 version of the PC. [[User:62.252.0.11|62.252.0.11]] 03:35, 12 April 2006 (EDT) |
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== Librivox == |
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[[Reinventing the OLPC]] |
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Human-read audiobooks for children as well as literature are going to be included in the OLCP project via content packs. A recurring idea I've seen crop up a few times is that of children recording their own audiobooks in return. What is the final quality of the built-in microphone? |
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== Make it for us, too == |
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[[Category:Hardware]] |
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All selling, commercial model, and fundraising-by-selling has been moved to [[Not for individual sale]] |
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[[Category:Hardware ideas]] |
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{{cleanup}} |
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Latest revision as of 07:13, 17 December 2008
Microphone
Sound Codec
The Hardware specification page says the Audio Codec is an Analog Devices AD1888, AC97-compatible audio codec.
The paper - 'The One Laptop per Child (OLPC) Audio Subystem' by Jaya (Alsa) provides useful information on the audio subsystem. The link is - The OLPC Audio Subsystem --Arjunsarwal
Microphone Sensor Input
The microphone input can be used to measure voltage or (using the Microphone bias voltage) resistance. This should enable us to use this as a form of sensor input with the audio analog to digital converter converting the sensor signal to a signal that can be displayed on the screen or logged by the computer. More info is required on the use of the codec in this mode.
- max voltage that can be withstood safely by the mic input
- Voltage corresponding to AD converter full scale.
- Bias voltage output (open circuit)
- Bias voltage output (short circuit)
- Frequency range of mic input
- anything else?
Uses of making measurement using the analog input port on the laptop
This section is useful for compiling a list of important and interesting uses for sampling analog input voltages using the analog input port of the laptop.It would also help in determining the end requirements of voltage range that would be required to be supported int he laptop at input.
Uses and their electrical requirements (Voltage range, bandwidth, Bias)
1. Checking the voltage of an AA/AAA/C/D type cells- Should be able to sample DC in the range 0-1.5V
2. Checking the voltage of a PP3(9V) type cell - Should be able to sample DC in the range 0-9V
3. Checking the voltage of a car battery - Should be able to sample DC in the range 0-15V
4. Interfacing an LDR/photo voltaic cell/Temperature sensor - Bias voltage required . Voltage range =
5. Robotics applications - The interface that is usually provided with commercial modules such as distance ranging modules is a 0-5V digital output. If the output voltage interface is RS232 type then voltage sampling requirements extend upto -12V - +12V. But then the XO has a serial port ? (Yes, but the connector is not exposed. --Walter 20:58, 24 June 2007 (EDT))
--dlarue 07:02, 15 January 2008 (PST)
Microphone data input
The microphone input jack can double as a dataport for some class of devices (when supporting a "DC-coupled" input mode), but a more general-purpose USB analog to digital device would be a great peripheral for the laptop. --Walter
Old thoughts
A built in Microphone would be usefully if dirt and echo/feedback could be controlled. If you have a microphone and speakers included with these laptops then then if you include a small piece of software they can be used as telephones or walkie talkies -- like an instant message local channel that is as easy to use as a CB radio. If the hardware looked like a radio, the operator could use it before they learned how to use the computer.
These are ideas related to both audio input and output. Please review the hardware specification to see what is already included. Some audio-related ideas are also dealt with in the Radio and Broadcast page.
Librivox
Human-read audiobooks for children as well as literature are going to be included in the OLCP project via content packs. A recurring idea I've seen crop up a few times is that of children recording their own audiobooks in return. What is the final quality of the built-in microphone?