I am considering buying an audio recording device to record spoken word for something like 8 to 12 hours at a time which is compatible with Linux, records intelligible sound when left in a pocket and isn't much more than around £30 ($50) though less would be better.
Does anyone use something like this or have any recommendations?

for that money...
any ol' android phone with sufficiently large memory/sdcard and some app from f-droid.org?
though i'm not sure about the "left in a pocket" part...

Hi...

I happened to find this page, which also gives a link to this product, the "Express Scribe Transcription Software' from NCH Software. I'm not sure if it will fit your needs and, unfortunately, it's no longer supported by the company. Up until the 15th, license fees are reduced, however, either way, it's still more than what you would like to pay.

Regards...

I am asking after dedicated hardware which I could either use off-the-shelf disposable batteries in or which have a recording life of at least 12 hours. A large SD card would probably cost more than the ~£35 (~$65?) Sony I found and an Android phone would likely not work for 12 hours non-stop.
I'm not sure what that product is? I am not looking for text-to-speech or anything like that but just a device I can set to record, leave for 12 or so hours at a time, then link to a Linux machine via USB and grab the files.

Recording time is determined by memory capacity and record quality. Recording from a pocket should not need high quality so 8-12 hours isn't a problem. Many record raw data and then require software (Windows or MAC) to convert to a MP3 or WAV format. I have not played with a voice recorder in a few years so I do not know what all is out there. The two below appear to record as MP3 and can connect to a PC as a memory drive so in theory should be compatible with linux. I personally have not use either one. I did have an older model Olympus but it was not compatible with linux.

SONY ICD PX333
Olympus WS-822

Thanks, I the the Sony was one of the ones I found doing an Amazon search. With most phones and portable media players being MTP nowadays I didn't want to assume that just because something recorded as mp3 I would have no issues just opening it under Linux.

273,
whatever floats your boat.

but my reply was serious.
you never said anything about "dedicated hardware" in your first post.

- depending on the sound quality, a few GB are plenty. a few GB == a few quid.
- with no sim card and no network connection, even a tired old android phone can do that for 12h.
- many people have both of the above just lying around == 0 (zero) quid.
- it doesn't even have to be android; my old nokia would have been capable of the same, since it had a slot for an sd-card and many, many standby-hours.

and all of these example produce linux-compatible output, i know from experience.

My apologies, I was rude but I'm not convinced I could pick up an device running Android for a price around my budget and be able to reliably record voice for a long period of time -- if you get 12 hours from a phone you ought to get more from something which doesn't keep a huge screen and many network features going?
As you mention though a cheap old phone could work -- I blame my age for expecting asking for a "Dictaphone" to mean hardware, so sorry once more.

about a year ago i got this model for 20euro (maybe 15pounds?).
and many of the even older "half-dumb" phones have slots for sd cards.
have a look on ebay.

the screen and networking are no. 1 + 2 battery drainers, but they are off during recording (be sure to check android settings to switch all networking and gps off) so without that even a weakened battery can keep the phone alive for a long, long time.

Might be worth a look at least, thanks.
I do wonder whether a device made for the purpose would work better though. To expand my idea is to be able to record every human interaction within my waking hours. The motivation being a kind of analysis of interactions, difficult to describe but sort of like CBT, a sort of self-improvement idea.
I can imagine a lot of eye-rolling going on but I am sure some will understand.