Bone conduction headphone test

1、Overview：

Bone conduction is a way for sound waves to travel to the inner ear, traveling through the vibrations of the skull to allow yourself to hear sounds. Compared with ordinary human ears hearing the sound of the outside world through air transmission, audio transmission through bone conduction can achieve the noise filtering effect of air conduction.

1.1、Overview of bone conduction headphones

Bone conduction headphones are headphones made using this bone conduction principle, and are divided into two categories: bone conduction speaker technology headphones, bone conduction microphone technology headphones.

Today we are talking about the former, bone conduction speaker technology earphones, which generate vibrations through a single vibrator and transmit them to the auditory nerve through the skull, so sound can be transmitted without passing through both ears.

Then, when you are making bone conduction finished earphones, you will definitely be troubled by the consistency of bone conduction earphones, and because of the particularity of bone conduction, you have high requirements for fixtures. The test equipment has a complete set of systems, which can quickly and accurately present the data of bone conduction finished earphone test items in a visualized manner.

 

2、Bone conduction headphone application test：

Bone conduction earphone speaker test items are frequency response, thd, sensitivity, impedance, polarity, Rub&Buzz, etc.

Microphone test items include frequency response, thd, sensitivity, etc.

2.1、Bone conduction headset test configuration

AM 581 Artificial mouth features:

• Accurately simulate the sound source of the sound field near the human mouth, suitable for frequency response, distortion and other acoustic parameter testing of telephone microphones and microphones (microphones)
• Higher low-frequency transducer efficiency (especially 100-200Hz)
• Extremely high sensitivity across the entire frequency band

ACC 1821 Single-axis accelerometer features:

• Single-axis vibration signal acquisition, integral welding, high stability

PM 6143 Audio data acquisition card features：

• 4 channels output, 4 channels input
• Built-in amplifier and built-in ICP power supply circuit
• MegaSig private drive, more stable test

AudioExpert audio analysis software features:

• Complete Audio Analysis Algorithm Library
• Supports automatic sequence editing
• Support LabVIEW call
• Support for remote control

Bone conduction headset custom fixture features:

• Test data is true
• more stable testing

U 982 Bluetooth adapter features:

• Support SBC\aptX Bluetooth protocol. (Megsin also provides other models of Bluetooth adapters that support AAC\LC3\BLE\LHDC and other Bluetooth protocols)
• Supports audio services such as A2DP, HFP (Narrowband, Wideband)
• Support SPP data transparent transmission

AB 03 shielding box characteristics：

• Audio RF Dual Isolation
• Support manual, program-controlled design
• Double button design, anti-pinch hand
• Rich access and output terminals

2.2、Bone conduction headset test link

Here is an example of the bone conduction headset test link:

1、Bone conduction headphone speaker test link:

The bone conduction finished earphone is connected and interacts with the U 982 Bluetooth adapter, and the audio signal is pushed by AudioExpert through the Bluetooth A2DP protocol to make the speaker of the finished earphone vibrate, and the ACC 1821 single-axis accelerometer cooperates with the customized fixture to collect the vibration signal to the PM 6143 audio data acquisition card, and then Send the collected signal back to AudioExpert audio analysis software for signal analysis.

2、2. Headphone microphone test link:

The finished earphone is connected and interacts with the U 982 Bluetooth adapter. AudioExpert pushes the audio signal to the PM 6143 audio data acquisition card and then sends out the sound signal through the AM 581 artificial mouth. The finished earphone microphone sends the collected signal back to the AudioExpert audio analysis software to analyze the signal.

Core components:

AudioExpert Test Platform

PM 6143, 4in, 4 out, Shuttle

U 982, BT Adapter, Shuttle

AM 581, Artificial Mouth, Low Distortion

ACC 1821-S5L1, Uniaxial Accelerometer