AEIRM is the impulse response measurement system which is used on a PC.
Impulse response is widely used for research, development and measurement in acoustics and its application grows infinite as well as the basic data of analysis and simulations. It uses a high performance audio interface and it has full synchronization for recording and playback of the signal. In addition, no longer extra analyzer is required when using this system. This system is very compact and portable.
- Sampling frequency: 96kHz, Resolution: 24 bit (depends on the audio interface)
- Measurements using M-sequence (Maximum Length Sequence, quasi-random signal) and the swept sine signal.
- Digital audio input / output is available (TOSLINK, AES/EBU)
- Frequency response function can be calculated
- The multichannel option enables efficiently multi-point simultaneous measurement
- Calculation of the inverse filter used in the room acoustic, acoustic signal processing and noise control, and convolution using the optional software
- The auralization system using convolution, can reproduce the measured sound field in the laboratory
- Microphone traverse system is supported
- Various applications using the high quality audio interfaces can be constructed with the similar system configuration
We conduct a jury evaluation to compare the difference among reflections from materials, based on the measured impulse responses. We could reproduce the delicate nuance of the sound quality and these approach is highly appreciated from our customers.
The sound pressure level sometimes increases at unexpected points when measuring road traffic or railway noise due to various kinds of reflected sounds. This phenomenon appears when there is an elevated highway over a road, railway track or tall buildings in the neighborhood. We can verify how much direct sound and reflected sound influences for overall sound pressure level by processing the direct sound component and the reflected sound separately using measured impulse response. Moreover, we can identify the buildings that cause the significant reflection by using our multi-channel measurement option.
We have various kinds of measuring equipments and maintain their performance by conducting periodical calibration.
Furthermore, we investigate by using the reliable impulse response about the change of frequency characteristics when setting the windscreen and the sound pressure level variations among sound level meters. We make an effort that we can conduct more reliable measurement.
| Hardware | |
|---|---|
| Sampling frequency | Analog input: 8000 - 96000 Hz Digital input: 32000 Hz, 44100 Hz, 48000 Hz, 88200 Hz, 96000 Hz |
| Resolution | 24 bit, 16 bit (selectable) |
| Number of Input channel | 1 or 2 channels
(Multi-channel option, maximum 4 channels) |
| Analog input/output | 1/4" TRS connector, switchable line level |
| Digital input/output | S/PDIF coaxial, RCA connector |
| Measureable impulse response length |
For MLS signal: At 96000Hz sampling frequency: 10.9 sec (max) At 48000Hz sampling frequency: 21.8 sec (max) For swept sine signal and user defined signal: Unlimited |
| Operating system | Microsoft Windows 95 / 98 / ME / NT 4.0 (SP3 or later) / 2000 / XP |
| System Requirements |
Recommended: CPU: Pentium 166MHz or faster RAM: 32MB or more HDD: 1 GB or more |
| Optional Software | |
|---|---|
| Multi-channel measurement option |
Up to 4 channels Please feel free to ask us if you need to measure more than 4CH. |
| Inverse filter option | for estimating the inverse filter of the impulse response. |
| Convolution option | for convoluting the measured impulse response to a sound. |