<p>The tech-specs of the sound card might help here. If you're lucky the device will come with a frequency response curve or at least something as broad as frequency response '0-96 kHz +/- X dB'. The market is quite exciting and probably driven by HiFi audio consumers (I've even seen 500 kHz soundcards...).</p>
<p>In my experience the soundcards can have a pretty flat frequency responses. Of course, the customer support may not be all that helpful in answering further questions in more detail. Here your friendly neighborhood oscilloscope can be very useful - feed in synthetic signals whose structure is known ( sweeps, white noise, sine waves) and check if the recorded signal's power spectrum and levels are as expected.</p>
<p>One main issue is really the continuous gain knobs that many consumer grade soundcards have. For example I've been using the RME Fireface series and they have markings only at 6, 30 and 60 dB at 7, 12 and 5 o'clock. The progression is non-linear and gain values at intermediate positions need to be measured manually! This is where 'scientific grade' equipment can be useful.</p>

CC BY-SA 4.0
2022-06-30T08:13:08.950Z
Unless the bit depth or the accuracy of the voltage reading of a sample is affected by the sampling rate, then the frequency response from the soundcard will be flat. 
What you really need to know then is the +/- dB (how accurately does it read the voltage).
The microphone/hydrophone will likely not have a fully flat frequency response.
Rasmus
CC BY-SA 4.0
2022-06-30T08:23:05.250Z
No idea of ADC internal workings here ,  :), good to know. The mic/hydro phone response will indeed to considered separately.
Thejasvi
CC BY-SA 4.0
2022-06-30T08:42:24.690Z
@Rasmus - it'd be great if you could expand the comment into an answer itself?
Thejasvi
CC BY-SA 4.0
2022-06-30T08:01:30.047Z
2022-06-30T08:01:30.047Z
Thejasvi
<p><strong>Consider Buying a USB DAC</strong></p>
<p>Sound cards mounted in the computer case, even expensive ones, are subject to electronic noise generated by the motherboard and other expansion cards. This is most noticeable when playing back faint signals, which are the bread and butter of passive acoustic monitoring.</p>
<p>One way to minimize the problem is to use a USB DAC instead of an internal sound card. These devices effectively move the noise-vulnerable analog circuit outside the computer case. Many models have integrated amplifiers, which make it easier to hear faint signals.</p>
<p>Much of the online advice on this topic is oriented toward audiophiles and gamers, but these may be useful:</p>
<p><a href="https://homestudiobasics.com/what-is-a-usb-dac/" rel="nofollow noreferrer">Beginners Guide: What is a USB DAC?</a></p>
<p><a href="https://youtu.be/K7vQFnn33H8?t=71" rel="nofollow noreferrer">Why a USB DAC is superior to a sound card</a></p>

CC BY-SA 4.0
2022-07-01T05:19:04.923Z
OP did mention Recordings. So IMO DAC are not the right answer
WMXZ
CC BY-SA 4.0
2022-07-01T23:03:31.977Z
May I ask what your reasoning is for that assessment?
Michael Pitzrick
CC BY-SA 4.0
2022-07-02T04:42:03.050Z
for me, recording means data acquisition using ADC and not playback of recorded data using DAC. Your answer focuses on DAC allowing only playback. If it were describing a CODEC , then yes that could be used for acquisition and playback.
WMXZ
CC BY-SA 4.0
2022-07-03T11:47:51.913Z
Thank you. I misunderstood the OP.
Michael Pitzrick
CC BY-SA 4.0
2022-07-01T02:27:21.763Z
2022-07-01T02:28:48.937Z
2022-07-01T02:28:48.937Z
Michael Pitzrick
<p>I've been seeing many relatively affordable USB audio interfaces (even multichannel ones, in fact) with &gt;= 96 kHz sampling rates. These seem like a cost-effective alternative to some of the more expensive solutions out there.</p>
<p>Are these okay to use for bioacoustic recordings? Specifically, do they have a flat frequency response, and what do I need to consider before using them?</p>
<p>Edit: <em>I'd been mistakenly using soundcard and audio interface interchangeably. Now clarified</em></p>

CC BY-SA 4.0
2024-04-16T18:49:27.303Z
As a followup to OP’s question… Are there any specific qualities to look for in an external soundcard? I have a Steinberg UR44 I use for personal stuff. I’m looking to purchase some equipment to start my journey into Bioacoustics, was wondering whether to look for something specific or if this wouldn’t make much of a difference? Thanks!
James Gabarretta
CC BY-SA 4.0
2024-04-17T10:39:14.793Z
Welcome @JamesGabarretta -- the format here is one question, and then all "Answers" should be actual answers. I converted your note to a "comment" on the question, but you could also consider submitting it as a new, separate question.
Dan Stowell
<recording><experiment-design><hardware>
Are consumer grade USB audio interfaces 'safe' to use for bioacoustics recordings?
# Are consumer grade USB audio interfaces 'safe' to use for bioacoustics recordings?

(Asked by: username_0 on 2022-06-30)

I've been seeing many relatively affordable USB audio interfaces (even multichannel ones, in fact) with >= 96 kHz sampling rates. These seem like a cost-effective alternative to some of the more expensive solutions out there.

Are these okay to use for bioacoustic recordings? Specifically, do they have a flat frequency response, and what do I need to consider before using them?

Edit: *I'd been mistakenly using soundcard and audio interface interchangeably. Now clarified*

**Tags:** recording, experiment-design, hardware

> **Comments:**
> **username_1**: As a followup to OP’s question… Are there any specific qualities to look for in an external soundcard? I have a Steinberg UR44 I use for personal stuff. I’m looking to purchase some equipment to start my journey into Bioacoustics, was wondering whether to look for something specific or if this wouldn’t make much of a difference? Thanks!  
> **username_2**: Welcome @username_1 -- the format here is one question, and then all "Answers" should be actual answers. I converted your note to a "comment" on the question, but you could also consider submitting it as a new, separate question.  

---

## 2 answers

### Answer by username_0 on 2022-06-30. Score: 6

The tech-specs of the sound card might help here. If you're lucky the device will come with a frequency response curve or at least something as broad as frequency response '0-96 kHz +/- X dB'. The market is quite exciting and probably driven by HiFi audio consumers (I've even seen 500 kHz soundcards...).

In my experience the soundcards can have a pretty flat frequency responses. Of course, the customer support may not be all that helpful in answering further questions in more detail. Here your friendly neighborhood oscilloscope can be very useful - feed in synthetic signals whose structure is known ( sweeps, white noise, sine waves) and check if the recorded signal's power spectrum and levels are as expected.

One main issue is really the continuous gain knobs that many consumer grade soundcards have. For example I've been using the RME Fireface series and they have markings only at 6, 30 and 60 dB at 7, 12 and 5 o'clock. The progression is non-linear and gain values at intermediate positions need to be measured manually! This is where 'scientific grade' equipment can be useful.

> **Comments:**
> **username_3**: Unless the bit depth or the accuracy of the voltage reading of a sample is affected by the sampling rate, then the frequency response from the soundcard will be flat.  What you really need to know then is the +/- dB (how accurately does it read the voltage). The microphone/hydrophone will likely not have a fully flat frequency response.  
> **username_0**: No idea of ADC internal workings here ,  :), good to know. The mic/hydro phone response will indeed to considered separately.  
> **username_0**: @username_3 - it'd be great if you could expand the comment into an answer itself?  

---

### Answer by username_4 on 2022-07-01. Score: 2

**Consider Buying a USB DAC**

Sound cards mounted in the computer case, even expensive ones, are subject to electronic noise generated by the motherboard and other expansion cards. This is most noticeable when playing back faint signals, which are the bread and butter of passive acoustic monitoring.

One way to minimize the problem is to use a USB DAC instead of an internal sound card. These devices effectively move the noise-vulnerable analog circuit outside the computer case. Many models have integrated amplifiers, which make it easier to hear faint signals.

Much of the online advice on this topic is oriented toward audiophiles and gamers, but these may be useful:

[Beginners Guide: What is a USB DAC?](https://homestudiobasics.com/what-is-a-usb-dac/)

[Why a USB DAC is superior to a sound card](https://youtu.be/K7vQFnn33H8?t=71)

> **Comments:**
> **username_5**: OP did mention Recordings. So IMO DAC are not the right answer  
> **username_4**: May I ask what your reasoning is for that assessment?  
> **username_5**: for me, recording means data acquisition using ADC and not playback of recorded data using DAC. Your answer focuses on DAC allowing only playback. If it were describing a CODEC , then yes that could be used for acquisition and playback.  
> **username_4**: Thank you. I misunderstood the OP.  

---

