SoundCheck概括

SoundCheck是以軟件為基礎的而功能強大的電聲和音頻電子測量系統(tǒng)，是可以根據(jù)特定技術指標為你量身定制。它具有多種數(shù)據(jù)采集選項和軟件模塊，并易于集成到生產和研發(fā)測試領域，是工程技術實驗室和生產車間的理想測試系統(tǒng)。 請瀏覽以下頁面來了解如何使用SoundCheck來測試各種單一和多通道音頻設備。

SoundCheck概括:什么是SoundCheck，它是由什么組成的，以及如何設置以達到你的精密要求？

SoundCheck的研發(fā)應用:是什么令SoundCheck成為音頻產品設計實驗室的特定選用測試系統(tǒng)？ 了解SoundCheck的度和功能，測試靈活性，和其他實驗室設備的兼容性和先進的撰寫功能。

SoundCheck生產線應用:為什么那么多的跨國公司擁有多套SoundCheck軟件用于生產線上？ 了解SoundCheck的速度，可靠性，抗噪性，生產線整合性和'數(shù)據(jù)庫 統(tǒng)計能力。

SoundCheck的性應用:當你在世界各地進行測試標準化，SoundCheck 在哪些方面有別于其他產品？了解其語言選項，共享程序，數(shù)據(jù)傳輸以及更多信息。

技術參數(shù):詳細的技術參數(shù)

特點:有關SoundCheck的更先進功能的詳細資料，例如虛擬設備和使用的算法

軟件套裝:關于SoundCheck的各同標準配置信息

應用設備:了解如何使用SoundCheck來測試揚聲器，麥克風，助聽器，電話機，耳機，話筒，MP3播放器以及更多的音頻電子設備。

SoundCheck -完備的研發(fā)工作室

SoundCheck是目前市場上完善的音頻測試系統(tǒng)。 它具有的測量分析，后處理和統(tǒng)計能力比得上那些價格貴幾倍的硬件音頻分析儀。另外，SoundCheck不僅僅是音頻分析儀 – 它相當于一個設備完善的研發(fā)工作室。它包含了實驗室里可以找到的所有典型設備的軟件版本 - 頻譜分析儀，實時分析儀，信號發(fā)生器，萬用表和示波器，因此你無須額外的硬件來進行測試。

準確和功能強大

前端的輸入設備，例如高端聲卡和National Instruments PCI/PXI-4461數(shù)據(jù)采集卡提供了可與昂貴的硬件測試系統(tǒng)相比擬的準確性，同時，該軟件特定的算法可以保證的測試結果和深度分析。 SoundCheck綜合發(fā)揮了電腦的計算機功能來達到快速的數(shù)據(jù)采集和分析。這些特點，結合程序先進的后處理性能，統(tǒng)計工具盒撰寫的選項，令該系統(tǒng)成為設計處理的強有力的工具。

完全控制和靈活測試

SoundCheck是測試開發(fā)人員的夢想。 你無需編程知識來寫復雜的測量程序，因為所有的測試是建立在通過直接點擊的圖形界面形成一系列的步驟的流程圖格式。用戶可以控制每個測試參數(shù)，而所有的控制都可以同時在界面中顯示以達到快速測試修改和研制。測試步驟控制所有的功能，包括設定硬件參數(shù)，校準，創(chuàng)建激勵值，采集，分析和保存數(shù)據(jù)及創(chuàng)建。

SoundCheck就像一個預編程步驟的綜合圖書館；每一步驟都可以修改，可以創(chuàng)建用戶自定義步驟及添加這些步驟到圖書館。整個測試程序是從單個的步驟，或從包含了幾個步驟的子程序中組合而來的，這樣，令建立和修改測試快而簡單。Co這些測試程序是可以保存的，所以整個測試可以通過點擊鼠標，就完成了設立，分析到，產生結論和存檔。測試步驟，程序和子程序都可以被復制，修改，保存，導出和發(fā)送電子郵件。 既節(jié)省了時間，又提高了測試程序的可重復性。

兼容性

盡管SoundCheck是一個完全獨立的系統(tǒng)，但它可以和任何品牌的輔助測試設備兼容，包括頭和軀干模擬器，仿真嘴和仿真耳，麥克風，功率放大器，電話測試接口，信號路由器等等。該系統(tǒng)同樣適用于你今后的測試需求 - 軟件會不斷升級，附加的模塊會不斷增添新的功能，而且這些升級都會是簡單和不昂貴的。

簡潔和性價比高

讓你的筆記本電腦真正發(fā)揮作用！ 如果你安裝SoundCheck系統(tǒng)在筆記本電腦上，你就能帶著具有音頻分析性能的實驗室，而無需硬件設備輕松上路了。 該系統(tǒng)不僅性價比高，而且特別適用于緊急處理生產線上的問題。

先進的撰寫功能

你可以通過導出數(shù)據(jù)自定義SoundCheck，或者輸出數(shù)據(jù)到Microsoft® Word或Excel之類的軟件包，或者如Microsoft Access, SQL或Oracle®之類的數(shù)據(jù)庫進行存檔，后處理或撰寫。 SoundCheck 同樣可以通過使用National Instruments’ 的Test StandTM或Active X®等軟件跟大型的測試應用程序想結合。

研發(fā)測試可以容易地轉化到生產線上

SoundCheck令生產線輕松地執(zhí)行跟研發(fā)實驗室同樣的測試 - 這樣可以確保用戶聽到跟設計工程師的預期完全一樣的效果。 由于沒有昂貴和復雜的硬件設備，SoundCheck 的價格在生產應用上是可承受的。它的速度很快并跟自動化生產線整合在一起。 重要的是，它先進的算法可以確保即使在高噪音的環(huán)境下測試結果仍然可靠。

同樣的測試程序可以根據(jù)研發(fā)用途和生產用途進行不同的配置。 例如，一個研發(fā)測試可以允許操作員修改輸入?yún)?shù)并輸出一個全面細致的分析，而生產線版本則只允許預設定為“單擊”操作來輸出簡單的“通過/失敗”結果給操作員，并將全面的測試結果寫到數(shù)據(jù)庫里。 因此，用戶可以為在公司內部開發(fā)的測試，同時和他們的制造工廠或第三方供應商共用該測試程序的生產線版本。這樣，無論在哪里生產，都易于進行質量控制

SoundCheck -快速可靠的生產線測試

SoundCheck非常適用于生產線測試。 它具有先進的算法，即使在高噪音的環(huán)境下，仍然可以進行快速和可重復的測試，和自動化生產線完全結合在一起。 它比人工測聽更可靠，比“堆架式”系統(tǒng)更簡單和經濟。 這一系列低預算的生產線軟件包提供了生產制造產業(yè)所需的功能，但成本明顯低于一套全面的研發(fā)系統(tǒng)。

快速

SoundCheck’先進的算法實現(xiàn)了極其快速的測試。 例如： 它能夠在短短的一秒鐘內執(zhí)行全面的傳感器分析 - 包括產生激勵信號，測量所需的參數(shù)，將結果和參考標準相比較，并以簡單的“通過、失敗”信息來顯示測試結果。 多通道軟件和硬件選項可以達到同時測量多個系統(tǒng)參數(shù)，以進行快速測試多通道設備（如混合主板或環(huán)繞聲系統(tǒng)）和批量測試。

可重復性

特殊設計的濾波器和分析算法可以分辨測試信號和背景噪音，從而提供了在嘈雜的生產制造環(huán)境下可重復的測試結果。此外，除了可以測量所有人工測聽出的錯誤外（如摩擦音，松散粒子等），SoundCheck還能夠檢測和定量那些不被人工測聽所發(fā)現(xiàn)的錯誤，如逆極性

容易使用

你可以設置測試為“點擊”或自動化操作以生成“通過/失敗”結果，同時，各種級別的密碼保護可以讓你控制誰可以進入和修改測試程序。 為了更簡化生產測試，你可以選擇中文版，令海外的生產線員工或第三方供應商明白屏幕上的指引。這些功能都被添加到系統(tǒng)中，提供簡單，無差錯的操作。

無停機時間

由于SoundCheck使用的硬件只是一臺電腦和一個的音頻聲卡 - 容易購買，并且低維護成本，所以它基本上消除了測試系統(tǒng)的停機時間。 如果發(fā)生故障，你自己的員工就可以通過使用標準的現(xiàn)貨供應配件來修復運行。你也可以選擇通過互聯(lián)網獲得Listen 公司工程師的即時遠程診斷。

和生產線相結合

SoundCheck和自動化軟件相兼容，并通過使用RS-232, IEEE-488, 藍牙，F(xiàn)ireWire， USB 和 TTL i界面跟條形碼系統(tǒng)，PLCs等硬件相連接。SoundCheckc可以通過LabVIEW 或其他支持ActiveX 命令(VB.NET, C#, C++, Java 等等)，所以它和大部分的測試平臺相兼容。 所有的測試結果都會被記錄在Sound Check 里面，或者輸出到其他軟件來進行統(tǒng)計程序控制。在生產自動化當中，你可以把測試設置為當被測設備到位時開始，不及格的設備會被從生產線中自動剔除。

數(shù)據(jù)庫和統(tǒng)計能力

你可以把測試設置為多數(shù)據(jù)輸出選項。 這些包括發(fā)送給生產線操作人員的通過比較參考標準值而產生的“通過/失敗”指示，自定義的SoundCheck，或發(fā)送到Microsoft® Access, SQL 或Oracle® 數(shù)據(jù)庫進行存檔，數(shù)據(jù)開發(fā)采集或撰寫的完整的測試結果記錄。 SoundCheck 還具有廣泛的統(tǒng)計分析工具欄，包括了Gage R&R，值，小值，平均值，標準偏差，收益，Cpk和平均值。

SoundMap Technical Specifications

Version 1.0

Time View

• Input File Data format
• SoundCheck Waveform
• Wave file (*.wav)
• TIM: MLSSA binary file format for time data
• Text files (documented format)
• Display of time waveform + zoom
• Analysis Parameters
• Choice of the transform: STFT, CSD, WV, Wavelet (see algorithms)
• Frequency resolution: Hz (STFT, CSD, WV) or 1/3…1/24 octave (Wavelet).
• Frequency resolution (in Hz)
• Time increment (in s)
• WV Smoothing size (in s)
• Automatic / manual setup
• Information
• Sampling frequency (Hz)
• Transform Overlap (%)
• Window/Wavelet duration (s).
• BT product (%)
• Analysis duration (s)
• Analysis completeness ( “Gap Free”):
• Number of spectra, lines/spectra, time-frequency pixels
• Bar-graphs for windows size, smoothing size and analysis duration

Multispectrum View

• Time-frequency intensity map with color coded levels and 2 side displays.
• Intensity Map (time-frequency-level)
• Color coded levels
• Unit = calibrated power spectral density in dB(ref. 1 U²/Hz)
• Choice of color scales: Rainbow, Fire, Sunset, Grey Scale…
• Choice of Dynamic Range
• 2D Max search.
• 2 cross-cursors (one absolute, one delta)
• Right Side Display= Frequency Display
• Global Energy Spectrum (U².s/Hz)
• Instantaneous spectrum (U²/Hz)= frequency slice at time location of cursor 1.
• Partial spectrum (U².s/Hz) between the 2 vertical cursors on the map
• Group Delay curve(s)
• 2 horizontal cursors coupled with the ones on the map.
• Bottom Display= Time Display
• Time wave, analyzed segment (U)
• Time slice (U²/Hz). The time slice is done at frequency location of cursor 1.
• Energy time curve (U²)
• Partial Energy time curve (U²) between the 2 horizontal cursors on the map
• Instantaneous Frequency (Hz)
• 2 vertical cursors coupled with the cursors of the map
• Analysis Parameters and Informations + Bargraphs as in the analysis front panel
• PhysicalUnit U.
• Energy Display: Total or Partial (defined by cursors)
• Save/recall map file
• Save jpg/bmp images

3D view (Color Waterfall)

• Log/Lin freq axis
• Color scale or Surface
• Full choice of view angle
• 3D Cursor
• Save jpg/bmp images

Algorithms

Transforms:

• STFT: Short-Term Fourier Transform with Gaussian window.
• WV:Smoothed Pseudo Wigner-Ville Transform with 2 independent Gaussian windows. Implemented in analytical form.
• CSD: Cumulative Spectral Decay with Cosine-Tapered (Tukey) Window. Low frequency limit inverse of window duration.
• Wavelet: Gaussian Analytical wavelet (Morlet). Fractional octave bandwidth and center frequencies.

Multispectrum:

• Global Energy Spectrum†: power sum of all spectrum of the multispectrum.
• Sub-Total Spectrum†: sum of all spectrum of the multispectrum, between the 2 verticals cursors.
• Energy Calculus†: sum of all time-frequency values of the whole multispectrum for the total energy, or in the box delimited by the 2 cross-cursors, for the partial energy.
• Energy-Time Curve: sum of all time slices of the multispectrum.
• Partial Energy Time Curve: sum of all time slices of the multispectrum, between the 2 horizontals cursors.
• Group Delay Curve†: centroid of each time slice over frequency.
• Instantaneous Frequency Curve:centroid of each frequency slice over time.

Loudspeaker Testing

System Overview

SoundCheck® is an easily configurable, Windows-based system for efficient and comprehensive measurement and testing of loudspeakers.

Production Testing

SoundCheck is a fast and accurate system for production line testing and loudspeaker QC. All quality-related parameters – both acoustical and electrical – are measured simultaneously, resulting in fast and thorough loudspeaker evaluation. SoundCheck’s unique stepped sine excitation signal (Stweep™) permits such detailed tests to be performed in as little as 3 seconds without sacrificing test accuracy, and its proprietary HarmonicTrak™ algorithm maintains measurement accuracy even in noisy environments.

The software can be configured for one-click access to commonly used tests, and various levels of operator control can be assigned to prevent modification of the test sequence. Results can be presented as a simple pass/fail indication, or a detailed failure mode analysis. Pass/Fail limits can be user-defined, determined by offsetting data from a measurement (e.g. ±3dB from the response curve of a reference loudspeaker), or determined statistically using SoundCheck’s statistical analysis module. Detailed results can be exported to other programs for additional processing, statistical control, and generating documents in standardized formats.

SoundCheck interfaces with barcode readers, footswitches, and other digital I/O devices such as TTL controlled relays, RS-232, and IEEE-488 to integrate fully with automatic production lines.

R&D Testing

SoundCheck is a powerful and flexible tool for the R&D laboratory. Its advanced measurement algorithms enable rapid characterization of prototypes, performing comprehensive tests such as frequency response, phase, sensitivity, distortion, directivity, impedance, and Thiele-Small parameters in a matter of seconds. SoundCheck is available with either a sound card or with National Instrument’s data acquisition cards for high precision measurements.

SoundCheck offers unrivalled flexibility at every stage in the test process. Input test signals include sine, noise, and any signal stored as a WAV file (e.g. multi-tone, impulse, tone burst, etc.). Customized test sequences are easily developed using SoundCheck’s unique point and click interface. SoundCheck can be easily incorporated into existing test programs that utilize ActiveX controls or National Instruments LabVIEW®.

Analysis tools include a FFT analyzer and an optional real time analyzer (RTA), which provides the R&D engineer with 1/1, 1/3, 1/6, 1/12, and 1/24 octave analysis. An optional analysis module enables the measurement of a loudspeaker’s free-field response and free-field harmonic distortion in a non-anechoic environment using a continuous logarithmic sine sweep. Soundcheck’s post-processing editor has many pre-programmed routines including Thiele-Small parameters, curve fitting to determine resonances, arithmetic operations, curve smoothing, and statistical functions. SoundCheck can also record the loudspeaker’s response as a WAV file for additional analysis.

Typical Loudspeaker Testing System Configuration

A typical loudspeaker test system consists of the SoundCheck Basic Software with optional Distortion, Post-Processing, Simulated Free-Field and Equation Editor modules, computer, sound card, audio amplifier, impedance box, microphone, and microphone power supply (options may vary depending upon application).

Features and Benefits

Same System for R&D and Production

With a common system for R&D and for the production line, it is easy for the tests developed by engineering to be performed on the production line. Identical virtual laboratories can be recreated around the world, making it easy for manufacturing to carry out the same tests as engineering, even if they are thousands of miles away.

Virtual Audio Test Bench

The SoundCheck software includes a virtual audio test bench. This includes a Signal Generator, Multimeter, Real Time Analyzer, Oscilloscope and Spectrum Analyzer. These virtual instruments provide exactly the same functionality as their expensive hardware equivalents, avoiding the need to purchase any additional stand-alone instrumentation.

One System, Many Options

SoundCheck is a modular system. Whether you want a basic sound card based system for production line testing of loudspeakers, or a sophisticated R&D system with National Instrument’s PXI-4461 dynamic signal acquisition module, for high accuracy laboratory measurements, we have a system to match your requirements and your budget.

麥克風測試

Microphone Testing

Features and Benefitsof SoundCheck for Microphone Testing

Frequency Response
SoundCheck features a variety of test signals and analysis methods for measuring the frequency response of a microphone. The source speaker can be calibrated such that any stimulus signal is equalized to remove the influence of the speaker’s magnitude and phase response.  SoundCheck’s stepped sine Stweep is the perfect choice for use in an anechoic chamber, test box, or for proximity tests. It can easily be optimized for the desired trade-off between accuracy and speed. For an extremely fast production test, use the Multitone stimulus, which plays a series of discrete frequencies simultaneously. You can even use an equalized speech or music WAV file as a stimulus and analyze the microphone’s response with the Transfer Function module.  

Simulated Free-Field Response
Not everyone who wants to measure a microphone’s free field response has an anechoic chamber at their disposal. Typically the problem with measuring free field response in a non-anechoic room is the influence of room reflections on the measurement. With SoundCheck’s Time Selective Response algorithm these reflections can be time-windowed out, and the resulting frequency response is anechoic and accurate. A log sine sweep is used as the stimulus.The algorithm calculates the impulse response, and a user-defined time window is placed around it, eliminating the influence of room reflections. 

 Directional Characteristics
Measuring directionality is a key part of any microphone testing. With SoundCheck, a microphone can be tested at multiple angles, and the data can be displayed on a single graph. This angular data can also be used to calculate the Directivity Index curve versus frequency, as well as generate polar plots for discrete frequencies. SoundCheck can also automate the entire process of directivity measurements by directly communicating with a turntable via GPIB or RS-232.    

Distortion
Most traditional audio analyzers are only capable of measuring one type of distortion, THD (total harmonic distortion). This measurement does not work for microphones, as the source speaker will almost always exhibit higher THD than the microphone under test. There is, however, another method.  SoundCheck can measure the distortion of a microphone using an intermodulation distortion technique and two separate sound sources. One source is used to produce a fixed tone and the other is used to produce a sine sweep. In this way, the harmonic distortion of the sources is excluded from the measurement, and only the selected intermodulation components from the microphone are measured.

Typical Microphone Test System Configuration

A typical microphone test system consists of the SoundCheck Basic System that includes stepped-sine sweep (Stweep™) excitation, frequency/phase response, and a calibrated high-end sound card. Optional SoundWare modules include the Real Time Analyzer and polar plotting. Turnkey systems including computer, reference microphones, test chambers, and audio amplifiers are also available.

Headphone Testing

Features and Benefitsof SoundCheck for Headphone Testing

Production Testing
SoundCheck offers fast and accurate system production line testing. All acoustical and electrical quality-related parameters including frequency response, distortion, rub and buzz, polarity, impedance and sensitivity are measured simultaneously, resulting in fast and thorough headphone evaluation. SoundCheck’s unique stepped sine excitation signal (Stweep™) permits such detailed tests to be performed in as little as 3 seconds without sacrificing test accuracy, and its proprietary HarmonicTrak™ algorithm maintains measurement accuracy even in noisy environments.

The software can be configured for one-click access to commonly used tests, and various levels of operator control prevent modification of the test sequence. Results can be presented as a simple pass/fail indication, or a detailed failure mode analysis. Pass/Fail limits can be user-defined, determined by offsetting data from a measurement (e.g. ±3dB from the response curve of a reference headphone), or determined statistically using SoundCheck’s statistical analysis module. Detailed results can be exported to other programs such as Microsoft Excel® for additional processing, statistical control, and generating documents in standardized formats.

SoundCheck interfaces with barcode readers, footswitches, and other digital I/O devices such as TTL controlled relays, RS-232, and IEEE-488 to integrate fully with automatic production lines.

R&D Testing
SoundCheck is a powerful and flexible tool for the R&D laboratory. Its advanced measurement algorithms enable rapid characterization of prototypes, performing comprehensive tests such as frequency response, phase, sensitivity, distortion, and impedance in a matter of seconds. SoundCheck is available with either a sound card or with National Instrument’s data acquisition cards for high precision measurements.

SoundCheck offers unrivalled flexibility at every stage in the test process. Input test signals include sine, noise, and any signal stored as a WAV file (e.g. multi-tone, impulse, tone burst, etc.).
In addition, amplitude sweeps can be generated using SoundCheck’s Stimulus Editor to study compression effects and determine maximum SPL. Customized test sequences are easily developed using SoundCheck’s unique point and click interface. SoundCheck can be easily incorporated into existing test programs that utilize ActiveX controls or National Instruments LabVIEW®.

Analysis tools include a FFT analyzer and optional real time analyzer (RTA), which provides the R&D engineer with 1/1, 1/3, 1/6, 1/12, and 1/24 octave analysis. An optional analysis module enables the measurement of a headphone’s free-field response and free-field harmonic distortion in a non-anechoic environment using a continuous logarithmic sine sweep. Soundcheck’s post-processing editor has many pre-programmed routines including Thiele-Small parameters, curve fitting to determine resonances, arithmetic operations to determine the difference between left and right earphone (including phase), diffuse field and free-field corrections, curve smoothing, and statistical functions. SoundCheck can also record the headphone’s response as a WAV file for additional analysis.

Features and Benefits
Same System for R&D and Production
With a common system for R&D and for the production line, it is easy for the tests developed by engineering to be performed on the production line. This makes it easy for manufacturing to carry out the same tests as engineering, even if they are thousands of miles away.

Virtual Audio Test Bench
The SoundCheck software includes a virtual audio test bench. This includes a Signal Generator, Multimeter, Real Time Analyzer, Oscilloscope and Spectrum Analyzer. These virtual instruments pro-vide exactly the same functionality as their expen-sive hardware equivalents, avoiding the need to purchase any additional stand-alone instrumentation.

One System, Many Options
SoundCheck is a modular system. Whether you want a basic sound card based system for production line testing of headphones, or a sophisticated R&D system with National Instrument’s PXI-4461 dynamic signal acquisition module, for high accuracy lab-oratory measurements, we have a system to match your requirements and your budget.

Typical Headphone Test System Configuration

A typical headphone test system consists of the SoundCheck Basic Software with optional distortion test module, computer, sound card, audio amplifier, artificial ear or test head, and microphone power supply for each ear (options may vary depending upon application).

Headset Testing

Applications of SoundCheck for Headset Testing Include:

• Analog wired headsets
• USB headsets
• Bluetooth headsets
• Stereo or Mono

Industry Standard Headset Tests

• Frequency response
• Sensitivity
• Phase
• Self-noise and signal-to-noise
• Distortion
• Max SPL
• Loudness Ratings
• Send sensitivity in a diffuse field
• Directional characteristics (polar plot)
• TIA 810/920

Features and Benefits of SoundCheck for Headset Testing

Frequency Response
SoundCheck features a variety of test signals and analysis methods for measuring the frequency response of both the receiver (speaker) and microphone path in a headset. A stepped sine sweep is ideal for simple analog headsets with minimal audio signal processing, and simple digital headsets with stable latency.  More advanced methods are necessary to test complex headsets or headset systems, because they do not react in a normal way to stepped sine signals. One example is a headset with substantial signal processing, such as a compressor, expander, etc. Other examples are digital devices, like Bluetooth headsets, that are prone to dropouts and latency shifts. These more complex headsets necessitate the use of broadband stimuli like noise, speech, or simulated speech (i.e. ITU-T P.50).  SoundCheck features the ability to use any WAV file as a stimulus, giving you the flexibility to choose your own source signal. These stimuli can even be corrected by a calibrated equalization curve when using a mouth simulator as the output source. 

Digital Communication
SoundCheck can communicate with any device that appears in the list of Windows audio devices.  This means that testing a Bluetooth or USB headset is as easy as connecting it to a PC and selecting it from a list in SoundCheck. No external digital interface is required!  A standard Listen-recommended soundcard is used for sending signals to a mouth simulator and receiving the signals from an ear simulator.  All of the audio to and from the headset is handled directly in the SoundCheck test sequence. 

Distortion
Measuring distortion is a key part of any headset testing.  Typically the receive transducer is tested for Total Harmonic Distortion and possibly Rub & Buzz.  SoundCheck’s HarmonicTrak algorithm accomplishes both of these, as well as generating a frequency response, from a single acquired waveform. The user has the option to select exactly which harmonics are analyzed, and a plot of distortion versus frequency is created.  A multitone stimulus can be used to test devices that do not work well with sine waves (e.g. Bluetooth headsets). The multitone analysis can also output a non-coherent distortion plot.  While this measurement is not identical to THD, it can be an effective metric for analyzing a device’s real-world performance. Another option is to use pulsed-noise distortion measurements, recently described in IEEE 269. 

Conformance to Standards
Some customers may have the desire or requirement to test their products according to an international standard. Listen offers two suites of test sequences for performing these measurements on headsets: TIA 810-B and TIA 920. Purchasing these sequence bundles saves a significant amount of test development time and is a great enhancement for an R&D system. 

Typical Headset Test System Configuration

Coming Soon

 Caption Coming soon too!