3D Nasometry

Portable nasometry unit

Nasality Microphone

The Nasality Microphone is a handheld nasometry unit that detects nasality in speech production. It uses a lightweight acoustic separator that is fitted with highly directional nasal and oral microphones. The portable design and USB compatibility makes the Nasality Microphone ideal for clinical or home-based speech therapy.

How nasometry works

The Nasality Microphone uses a special lightweight acoustic separator that is positioned above the upper lip. The acoustic separator is fitted with independent nasal and oral microphones.

Nasality is represented by a numerical value called nasalance, which is defined as the percentage of the total acoustic energy that is nasal:

Acoustic Nasalance

Nasalance, which is calculated for voiced sounds only, can be monitored in real-time for biofeedback, or recorded for off-line assessment.

Software options


NasalanceViewer is easy-to-use Windows software that provides an ideal introduction to nasometry:

  • Provides real-time visual feedback of nasalance
  • Provides off-line objective analysis of nasalance
  • Provides auditory playback of speech production
  • Waveform display with adjustable target cursor
  • Skywriter game with adjustable target cloud
  • Simple to use interface
  • Windows 10, 8, 7 and Vista compatible
  • 10 user license

NasalanceViewer 3D

In addition to providing numerical displays of nasalance and nasal-oral speech, NasalanceViewer 3D uses state-of-the-art computer animation and 3D modelling techniques to approximate velopharyngeal closure and nasal-oral airflow.

The animated 3D model consists of the lips, teeth, tongue, lower jaw, hard palate, soft palate and uvula. The transparency of these articulators can be adjusted to reveal hidden structures, and the model can be rotated 360°. Airflow clearly illustrates the difference between nasal, oral, voiced and voiceless sounds.

Nasal airflow Oral airflow
Nasal airflow (soft palate lowered) Oral airflow (soft palate raised)
Voiced airflow Voiceless
Voiced airflow (intermittent flow) Voiceless airflow (continuous flow)

Additional features include:

  • Real-time visual feedback of nasalance
  • Off-line objective analysis of nasalance
  • Auditory playback of speech production
  • Photorealistic and stylised views
  • Windows 10 64-bit and 8 64-bit compatible

icSpeech Professional Edition

The Nasality Microphone is also compatible with icSpeech Professional Edition, which supports a wealth of additional features, including:

  • Additional displays: bar, waveform, spectrogram and video
  • Additional parameters: nasalance, pitch, timing, nasal and oral acoustic energy
  • Six games with adjustable targets and rewards
  • Extensive analysis features
  • Data export facility
  • Recorder with picture and word prompting
  • Combines nasometry with EPG, airflow, voicing and video data
  • Windows 10, 8, 7 and Vista compatible
Nasalance Bar Nasalance real-time waveform Games

Bar display

The real-time Bar is a useful biofeedback tool that shows a simple bar, which moves upwards with increased nasalance. This allows the user to monitor nasality, make corrections, and instantly see the result.

Waveform display

The real-time Waveform display is often used in therapy because it allows the user to see the dynamics of their speech during the utterance of complete words or phrases.


Each of the six interactive games feature adjustable targets, rewards and can be controlled with nasalance, pitch, nasal or oral acoustic energy.

Acoustic separation

For accurate results, it is important that there is a good seal between the face, just above the upper lip, and the acoustic separator. This prevents oral sounds being detected by the nasal microphone and vice versa. To ensure a good seal, the acoustic separator incorporates large and small facial contours. Simply rotate the nasal and oral microphones so they point to the side that best fits the contours of the face. The acoustic separator is also fitted with highly directional noise cancelling microphones, which further improve the acoustic separation.

acoustic separator

Microphone matching

For accurate results, it is also important that the nasal and oral microphones are acoustically matched. During the manufacturing process, both the sensitivity and frequency response of the nasal and oral microphones are individually matched. This eliminates the need for the user to calibrate the Nasality Microphone. The microphone matching characteristics are supplied with each device.


The Nasality Microphone is easy to dismantle and clean. The foam windshields covering the nasal and oral microphones can be removed and replaced, or washed in warm soapy water. The individual microphones, acoustic separator and handle can be removed and thoroughly cleaned with disposable disinfection wipes.

Nasality Microphone cleaning



Left channel Nasal speech
Right channel Oral speech
Type Electret condenser
Directionality Uni-directional
Frequency response (band-pass filter disabled) 100 – 15,000Hz
Frequency response (band-pass filter enabled) 350 - 650Hz
Sensitivity -40dB at 1kHz (0dB = 1V/Pa)
Output impedance 2.2k ohm
Power supply 1.5V – 10V

USB audio adaptor

Microphone input 2 channel stereo
Sample rates 48kHz, 44.1kHz. 16kHz and 8kHz
Resolution 16bit
THD -90dB
Frequency response 20 – 20,000 Hz
Input range 0 – 1.25 Vrms
Dynamic range 96dB
Record gain range -6 - 33dB
Supply voltage 4.5 - 5.5 VDC via USB
Total power consumption 33 mA

System requirements

Supported operating systems Windows 10, 8, 7 or Vista
Supported computers Desktop, laptop, tablet
CPU Minimum 1 GHz Intel® Pentium® or equivalent
Memory Minimum 1 GB of RAM
Storage 100 MB of free hard disk space
Connectivity USB 1.0, 2.0, 3.0
Power USB bus powered

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Nasality Microphone Package

Package includes:

  • Nasality Microphone
  • Carry case
  • Four microphone windshields
  • User manual
  • 12 months guarantee
  • NasalanceViewer software (optional)
  • NasalanceViewer software 3D (optional)
  • icSpeech Professional Edition software (optional)
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"Thanks so much for your help and speedy response.

We are being supported by the team at The Spires clinic in Salisbury Hospital. They are an amazing team of experienced and friendly staff and have enabled our daughter to communicate both through operations and speech therapy over the last 8 years.

We are currently working with Philippa Humes who has loaned us the microphone to practise with our daughter inbetween sessions.

She has some mild learning difficulties and visual aids really help with her learning. I'm finding the software adds an element of fun to the sessions which could otherwise prove a little tedious and it also helps me to listen for and recognise subtle sounds I wouldn't normally pick up on.

I'm hoping it will help us to continue to fine tune her speech and help to reduce the nasal quality she still has with certain sounds."

United Kingdom


"I tested your device using various speech samples (mainly, /ba-ba-ba/; /ma-ma-ma/; babababa/) mimicking various nasality severities. It worked beautifully and in my opinion it is very reliable. Great job for a reliable device with a reasonable price."

General Abdelrahim Attieh, Ph.D., SLP, Consultant Speech, Voice, & Swallowing Specialist
King Hussein Cancer Center
Amman, Jordan