Microphone + speaker - clever idea needed

[Munroast]

I brew my own beer, and I have a big heavy insulated box that sits over the fermenting bucket to keep a steady temperature. I regularly need to lift this insulated box off to view the air lock and see how quick the bubbles are coming through.

What I would like is a little microphone to attach to the air lock and linked to something that could repeat the noise of the bubbles coming through.

It does not need to be wireless, but it needs to be cheap

Any thoughts ?

and NO, I don't want the airlock outside of the box, even if it is the obvious solution.

 

[SFK]

How about a Audio Baby monitor:
https://www.ebay.co.uk/itm/Motorola...644704&hash=item1efe2ebc95:g:AbYAAOSwrHJdLb~3

 

[SFK]

For three times the cost you could even have a video version
https://www.ebay.co.uk/itm/2-Baby-M...518479?hash=item56af9d718f:g:RlcAAOSwoPtbBoVw

 

[Munroast]

rather annoyingly in a 'big tidy up' I threw one of those out last year. Anyway, that is way over budget, cost wise, I'm thinking just a few dabs of solder.


Anyone no about hearing aids ? could an old one be taken apart and a long wire added between mic and speaker

 

[Gerrydelasel]

I wonder if you could find a cheap powered PC speaker with a mic input? Kinda like a really cheap little PA system!

 

[OwainDIYer]

By the time you've paid for any bits, postage on top, then you'd be as well buying something.

Simplest would be a carbon telephone transmitter, telephone receiver, and a battery, as it wouldn't need an amplifier. But that will cost out more than buying something. eg

https://www.ebay.co.uk/itm/intercom/223582400210

https://www.ebay.co.uk/itm/intercom2/183887787409

both 99p plus £3.30 or £3.99 postage.

Lateral thought - a stethoscope. From about £4 on ebay.

Or as a home brewer you probably have tube and a funnel so could make up some form of listening device yourself.

 

[Munroast]

By the time you've paid for any bits, postage on top, then you'd be as well buying something.

Simplest would be a carbon telephone transmitter, telephone receiver, and a battery, as it wouldn't need an amplifier. But that will cost out more than buying something. eg

https://www.ebay.co.uk/itm/intercom/223582400210

https://www.ebay.co.uk/itm/intercom2/183887787409

both 99p plus £3.30 or £3.99 postage.

Lateral thought - a stethoscope. From about £4 on ebay.

Or as a home brewer you probably have tube and a funnel so could make up some form of listening device yourself.

I have some old telephones - where would I start ?

 

[foxhole]

Spare mobile phone ? Can be used with “Presence” app over WiFi , can monitor sound or picture or both and give you alerts .

 

[OwainDIYer]

I have some old telephones - where would I start ?

https://www.instructables.com/id/Simple-Intercom-From-a-Pair-of-Old-Corded-Phones/

 

[bernardgreen]

A gurgleometer.......

A mad idea ( but they thought the Wright brothers were mad ) which I might get time to try this week end.

A lighr beam through the liquid and onto a photocell. The analogue output from the photocell to lous speaker. Bubbles moving in the liquid will affect the passage of light through the liquid and hence the amount reaching the photo cell, this may be enough to produce audio.

 

[bernardgreen]

Regret I didn't time to get round to trying this idea. If still looking for a solution then let me know.