让linux脚本输出声音,即使在linux中没有麦克风，声音输出也会出现在声音输入中...

我正在尝试同时播放声音和记录来自压电传感器的电压输出。为此，我将我的声卡模拟输出连接到扬声器，并将我的声卡模拟输入连接到压电传感器。在

当我录下来自传感器的信号但没有播放声音时，它工作得很好。但是，当我在录音过程中播放声音时，我可以看到我正在播放的声音在传感器的信号中，就好像声音板的输出和输入是连接在一起的。最奇怪的是，即使我拔下传感器，输出信号仍然存在于录音中。在

换句话说，问题是：我开始录音，当我开始播放声音时，它会出现在传感器的信号中(即使在扬声器关闭的情况下)。在

我只使用ALSA，没有安装pulseaudio。我使用python(和pyaudio)来生成声音信号，将信号写入声音板输出，并从声音板输入读取数据。我也做了大胆的测试，但结果是一样的。我还用录音带测试：$ arecord --channel=1 --rate=128000 --format=S32_LE Test.wav

然后：

^{pr2}$

然后停止了录音。当我玩的时候测试.wav，播放文件的所有声音信号都在那里。在

我知道这听起来很明显，但我想说的是，在设置的任何地方都没有连接麦克风。在

以下是一些信息：

======================

盒子：$ uname -a

Linux MalfattiTux 4.1.12-gentoo #3 SMP Thu Jan 21 17:24:27 BRST 2016 x86_64 Intel(R) Core(TM) i7-4710HQ CPU @ 2.50GHz GenuineIntel GNU/Linux

音频板：$ lspci | grep -i audio

00:03.0 Audio device: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor HD Audio Controller (rev 06)

00:1b.0 Audio device: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller (rev 05)## Heading ##

输出设备：$ aplay -l

**** List of PLAYBACK Hardware Devices ****

card 0: HDMI [HDA Intel HDMI], device 3: HDMI 0 [HDMI 0]

Subdevices: 1/1

Subdevice #0: subdevice #0

card 0: HDMI [HDA Intel HDMI], device 7: HDMI 1 [HDMI 1]

Subdevices: 1/1

Subdevice #0: subdevice #0

card 0: HDMI [HDA Intel HDMI], device 8: HDMI 2 [HDMI 2]

Subdevices: 1/1

Subdevice #0: subdevice #0

card 1: PCH [HDA Intel PCH], device 0: ALC3239 Analog [ALC3239 Analog]

Subdevices: 1/1

Subdevice #0: subdevice #0

card 1: PCH [HDA Intel PCH], device 1: ALC3239 Digital [ALC3239 Digital]

Subdevices: 1/1

Subdevice #0: subdevice #0

输入设备：$ arecord -l

**** List of CAPTURE Hardware Devices ****

card 1: PCH [HDA Intel PCH], device 0: ALC3239 Analog [ALC3239 Analog]

Subdevices: 1/1

Subdevice #0: subdevice #0

要播放和录制的Python代码(最小工作示例)：import array

import pyaudio

import random

Rate = 128000

SoundPulseDur = 5 # in seconds

print('Generating sound pulse...')

SoundNoise = [random.random() for _ in range(round(Rate*SoundPulseDur))]

SoundPulse = [SoundNoise[ElI]*2-1 for ElI,ElV in enumerate(SoundNoise)]

SoundPulse[-1] = 0

print('Interleaving channels...')

SoundList = [0]*(2*len(SoundPulse))

for _ in range(len(SoundPulse)):

SoundList[_ *2] = SoundPulse[_]

SoundList[_ *2+1] = 0

Sound = array.array('f')

Sound.fromlist(SoundList)

Sound = bytes(Sound)

print('Generating sound objects...')

# Output

p = pyaudio.PyAudio()

Stimulation = p.open(format=pyaudio.paFloat32,

channels=2,

rate=Rate,

output=True)

# Input

q = pyaudio.PyAudio()

InOn = False

RecStop = True

def InCallBack(in_data, frame_count, time_info, status):

if InOn:

global SoundRec

SoundRec.append(in_data)

if RecStop:

InFlag = pyaudio.paComplete

else:

InFlag = pyaudio.paContinue

return(None, InFlag)

Reading = q.open(format=pyaudio.paFloat32,

channels=1,

rate=Rate,

input=True,

output=False,

stream_callback=InCallBack)

SoundRec = []

Reading.start_stream()

RecStop = False; InOn = True

Stimulation.write(Sound)

InOn = False; RecStop = True

Reading.stop_stream()