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Did Raspberry Pi 3 add audio input? I'm new to RPi and interested in doing speech recognition but noticed input has been missing for previous versions.

If it hasn't, what is the best way for me to go about recognizing speech on RPi3? Thank you.

corysimmons
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    Welcome - look at cheap USB sound card dongles, they typically have an input as well as an output port. Should cost no more than $5 via EBay etc. – Phil B. Feb 29 '16 at 20:48
  • Nope - but there are plenty of hats which provide audio input. http://elinux.org/index.php?title=RPi_Expansion_Boards#Sound – Matt Mar 17 '17 at 20:07

3 Answers3

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The product announcement does not list any form of audio in. You could use a USB device as mentioned by Phil, or use a hat that's designed for the job.

Jacobm001
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    What is a "hat" (Google isn't being very helpful)? Also, what are the advantages to an expensive card like that vs. a $5 input? – corysimmons Feb 29 '16 at 21:20
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    Hats are addon boards designed specifically for the RPi. The hat will give you better quality, and won't add a lot of the overhead nightmare known as USB. It really depends on what level of quality you need, what types of inputs, and what your budget looks like. – Jacobm001 Feb 29 '16 at 21:25
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    Thanks I'm just looking for voice recognition. Preferably like from across the room. Like I want to be able to yell "go to youtube.com" from my couch. :) Think a $5 usb dongle and $5 3.5mm mic could do that? – corysimmons Feb 29 '16 at 22:03
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    @corysimmons were you able to find a microphone solution? I got a Raspberry Pi 3 and need a microphone for voice recognition too. – Web User Nov 04 '16 at 16:00
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    There are now more addons and hats which give line inputs to the Pi, check here for a short list : http://elinux.org/index.php?title=RPi_Expansion_Boards#Sound – Matt Jan 16 '17 at 12:21
  • The hat listed in this post is only one of many. This answer also links out to a page, it doesn't explain why this is the case - that there is not audio input. – Matt Mar 17 '17 at 20:04
  • @Matt: How would you expect me to answer the question as to why the designers did not include such an input? When I wrote the answer over a year ago they had not put such explanations in the blog post and to my knowledge they still haven't. – Jacobm001 Mar 18 '17 at 01:29
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That is correct, there is no audio input. The Pis generate analogue audio output using simple pulse width modulation (PWM) which is an efficient way to make output audio, but in the case of the Pi, it lacks great analogue separation. To get audio input, the Pi would have to have a dedicated audio codec, which it doesn't.

A lot of people mention USB sound cards which can readily be used with the Pi systems. There are other GPIO based sound cards which can also provide input audio lines ... check here for a non comprehensive list. Some of them also have microphones built in or microphone inputs, or lastly line inputs with which you can use a microphone preamp.

USB sound cards tend to have longer latencies (mode delay) as they have to buffer audio to send over USB (using the UAC/UAC2 protocol).

Matt

Matt
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  • Could you please include some specific detail in your answer, link only answers are generally discouraged. – Darth Vader Sep 03 '16 at 08:35
  • Thanks for the feedback Darth, I have now altered my answer to include info on why there isn't audio input as well as mentioning USB sound cards. – Matt Sep 04 '16 at 11:23
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You can use one of those USB sound cards, or if you don't want to hog up USB ports but don't mind using the GPIO pins, you can use the Cirrus Logic Sound Card (audiophile-grade hardware though, fairly expensive)

Maxthon Chan
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