FAQ

Yes. The Nasality Microphone is widely used with children, including in school-based programmes and university clinic settings. The lightweight acoustic separator is designed to comfortably fit different facial contours. The NasalanceViewer software includes gamified displays — including a Skywriter game — that work well when taking nasalance measurements from younger speakers. The device has been used in peer-reviewed research with paediatric populations across multiple countries.

Both instruments measure nasalance using an acoustic separator positioned above the upper lip. The primary differences are portability, cost, and ease of use.

The Nasality Microphone is a handheld, USB-powered device that connects to any Windows laptop or tablet and is significantly more affordable than the PENTAX Nasometer. The Nasality Microphone requires no calibration, since the nasal and oral microphones are individually matched during the manufacturing process.

The Nasality Microphone is handheld rather than head-mounted, which many users find more comfortable and practical, particularly when working with children. Disposable foam windshields protect the microphone elements and prevent cross contamination between speakers. Its portable design makes it well suited to home visits, fieldwork, and university programmes where budget and portability matter.

The Nasality Microphone has been used as a validated comparator in peer-reviewed research.

The acoustic separator is positioned above the upper lip and does not enter the mouth or nasal passage. Disposable foam windshields are available as replacement accessories and are recommended for use between different speakers to protect the microphone elements. The acoustic separator and housing can be wiped with standard surface disinfectants. Please contact us for specific hygiene guidance relevant to your setting.

Normative nasalance scores vary by language, speaker age, and the passage stimuli used during measurement. Published research using the Nasality Microphone provides population-specific normative values. For example, Peris-Hernández, Rosell-Clari and Kummer (2024) established normative nasalance values for Spanish-speaking children aged 3 to 5 years using the Nasality Microphone, reporting high internal consistency across vowels, syllables, and phrases.

Yes. The Nasality Microphone has been used in peer-reviewed research published in international journals, including studies measuring nasalance in cleft palate and hypernasal populations, and studies in which the Nasality Microphone was used as a comparator instrument when validating novel nasometry systems. When citing the device in publications, please reference it as: Nasality Microphone, icSpeech, a division of Rose Medical Solutions Ltd., Canterbury, UK. A list of publications featuring icSpeech technology is available on the publications page.

The Nasality Microphone uses a fixed band pass filter with a centre frequency of 500Hz and a frequency range of 350–650Hz to isolate the frequency range that best reflects nasal resonance and to minimise interference from irrelevant acoustic information. Using a fixed band pass filter ensures that nasalance scores remain consistent across different sessions, subjects, and nasometry devices. The nasal and oral microphones are also individually matched during manufacturing for both sensitivity and frequency response, further ensuring measurement accuracy.

NasalanceViewer, NasalanceViewer 3D, and icSpeech Professional Edition currently support Windows 10 and Windows 11 only. The Nasality Microphone hardware uses standard USB audio and is not platform-restricted, but the software requires Windows. Users working in Mac environments may wish to run Windows via Boot Camp or a virtual machine. Please contact us to discuss your setup — we are happy to advise on the best approach for your environment.

The Nasality Microphone connects to a local Windows computer and captures nasalance data locally. A speech professional or trained assistant can operate the device with the speaker present, while a remote supervisor observes via video call. Nasalance data and recordings can be exported and shared with a remote colleague for review. Direct real-time streaming of nasalance data over a video connection is not a standard configuration. Contact us to discuss remote working workflows.

Yes. icSpeech supplies universities, NHS trusts, and research institutions across the UK and internationally. We provide formal quotations suitable for institutional procurement processes, grant applications, and NHS purchasing frameworks. Please use the Get Quote form and indicate your institution type — we will respond promptly with appropriate pricing and documentation.

Yes. LinguaGraph is widely used with children, including in school-based programmes, university clinics, and cleft palate services. The biofeedback games, regional colour coding, and the 3D tongue model make it particularly engaging and intuitive for younger speakers. However, several factors should be considered when using EPG with children:

Minimum age — The EPG palate clips to the upper teeth and requires a stable dentition for accurate fitting and reliable retention. Deciduous dentition is generally established by around 3.5 years and stable until approximately 6 years, making 6 years a practical minimum age for most speakers. Children in the mixed dentition stage (6–13 years) may require palate alteration or replacement as their dentition changes.

Cognitive ability — EPG requires the speaker to understand the relationship between tongue placement and the visual display. A certain level of cognitive ability is a prerequisite for effective use, as noted in the Cochrane review of EPG therapy (Lee et al., 2009).

Acclimatisation — A practice palate, which contains no electrodes or lead out wires, can be used to help speakers adjust to wearing the EPG palate before sessions begin. Increased saliva production is common initially and usually settles with acclimatisation.

A practice palate is a custom-made palate that contains no electrodes or lead-out wires. It is used to help speakers acclimatise to wearing an EPG palate before sessions begin.

Wearing a practice palate allows the speaker to adjust to the sensation of the palate in the mouth, including the increased saliva production that is common initially. Acclimatisation with a practice palate can reduce the time needed to settle into EPG sessions and reduces the incidence of false contacts caused by excess saliva.

Contact us for further information on practice palates.

Yes — each speaker requires their own custom-made artificial palate. The palate is moulded to fit the individual speaker's hard palate and clips to their upper teeth. Because palate shape varies significantly between individuals, a standard or universal palate is not available.

EPG palates are manufactured from a plaster model of the speaker's upper palate and teeth. A qualified dentist takes an impression using high quality alginate — note that the requirements differ from a general dental impression, as the impression must extend to include the gum area immediately behind the posterior molars to accommodate the lead-out wires. The plaster model is then sent to the laboratory for palate manufacture. Alternatively, an intraoral 3D scan can be used to produce a 3D printed model, which is sent to the laboratory in place of a traditional plaster impression.

EPG palates typically take 2–3 weeks to manufacture from receipt of the plaster model at the laboratory. It is recommended that a photograph of the plaster model is emailed to enquiries@rose-medical.com before sending, to confirm the model is suitable for palate manufacture.

Contact us for further guidance on the impression and plaster model requirements.

Yes. An intraoral 3D scanner can be used to capture a digital record of the speaker's upper palate and teeth, removing the need for a traditional alginate impression. The digital file is used to produce a 3D printed model, which is then sent to the laboratory in place of a traditional plaster cast.

Note that the dental laboratory cannot currently accept digital files directly — a physical model is still required. However, a 3D printed model produced from an intraoral scan is a suitable alternative to a plaster cast and may be more convenient in settings where access to a dentist for impression-taking is limited.

Contact us to discuss this workflow before proceeding.

The EPG palate kit enables an orthodontic technologist to manufacture an EPG palate locally. Each kit contains:

• 62 silver electrodes with attached leads (spare electrodes included)
• EPG connector board
• EPG connector board cover
• Heat shrink tubing
• Instruction manual

The palate kit is particularly useful for institutions with access to an in-house orthodontic technologist, or in countries where shipping time and costs make overseas palate manufacture impractical.

EPG palate kits are available to order from icSpeech. Contact us for further information.

To clean the EPG palate after use, rinse in warm water. If necessary, clean gently with a soft toothbrush and mild detergent, then wipe dry with a soft tissue. Avoid getting the palate connector wet. Always place the palate back on the plaster cast when not in use, and avoid subjecting the wires to undue tension or excessive coiling.

Note that eating salty or sugary foods immediately before wearing the palate can cause false contacts. In these circumstances the speaker should rinse their mouth with water before fitting the palate.

For specific decontamination guidance relevant to your clinical or institutional setting, please contact us.

False contacts are electrodes that appear to register tongue contact even though the tongue is not actually touching that part of the palate. They occur in two main forms:

• Flickering contacts — individual electrodes that randomly activate and deactivate, often rapidly. Most common during the initial acclimatisation period or when the speaker has eaten salty or sugary foods before fitting the palate.
• Sticky contacts — a cluster of adjacent electrodes that remain persistently active regardless of tongue position. Caused by excess saliva bridging a group of electrodes rather than activating them intermittently.

How to minimise false contacts

• Allow at least 15 minutes acclimatisation time before a session
• Ask the speaker to rinse their mouth with water before fitting the palate
• Use a practice palate to aid acclimatisation
• Frequently remove the palate and wipe with a paper tissue
• Avoid eating salty or sugary foods immediately before fitting the palate
• Ensure the sensitivity is correctly adjusted using the sensitivity control on the LinguaGraph unit
• Increase the position of the Remove false contacts slider in the software settings

Electropalatography and ultrasound tongue imaging (UTI) are complementary rather than competing techniques — each captures articulatory information that the other cannot.

EPG measures exactly where and when the tongue contacts the hard palate across 62 electrode positions. It provides precise, quantifiable data on tongue-palate contact patterns, but cannot show tongue shape or movement in areas away from the palate.

Ultrasound shows the shape and movement of the tongue body in real time, including regions that do not contact the palate. However, ultrasound cannot directly measure tongue-palate contact.

A key advantage of EPG is its ability to reveal tongue–palate contact patterns that cannot be directly observed or reliably identified through perceptual analysis alone. Research has shown that lateral fricatives, for example, are easily visualised by EPG but not by midsagittal ultrasound (Cleland et al., 2025).

icSpeech Professional Edition and LinguaGraph can be used simultaneously with ultrasound tongue imaging, allowing both contact patterns and tongue shape to be recorded in a single session.

Yes. LinguaGraph has been used in peer-reviewed research published in international journals, including studies in phonetics, cleft palate speech, verbal dyspraxia, cerebral palsy, and cochlear implant research. When citing LinguaGraph in publications, please reference it as:

LinguaGraph EPG System, icSpeech, Rose Medical Solutions Ltd., Canterbury, UK.

A list of publications featuring icSpeech technology is available on our publications page.

LinguaView, LinguaView 3D, and icSpeech Professional Edition currently support Windows 10 and Windows 11 only. The LinguaGraph hardware uses a standard USB connection and is not platform-restricted, but the software requires Windows. Users working in Mac environments may wish to run Windows via Boot Camp or a virtual machine. Please contact us to discuss your setup.

Yes. LinguaGraph uses the Reading EPG palate design, which is the same design used by WinEPG (Articulate Instruments). Palates manufactured for WinEPG are therefore compatible with LinguaGraph.

Note that Articulate Instruments ceased EPG production in 2013. Existing WinEPG users looking to replace or upgrade their system may wish to consider LinguaGraph as a compatible alternative. Contact us to discuss compatibility with your existing palates.

LinguaGraph connects to a local Windows computer and captures EPG data locally. A speech professional, trained assistant, or researcher can operate the system with the speaker present, while a remote clinician or researcher observes via video call. The EPG display can be shared in real time using screen sharing on any standard videoconferencing platform such as Zoom or Microsoft Teams, allowing a remote clinician or researcher to observe the session live. Recorded EPG data can also be exported and shared for offline review.

Contact us to discuss remote working.

Yes. icSpeech supplies universities, hospitals, and research institutions globally. We provide formal quotations suitable for institutional procurement processes and grant applications. Please use the Get quote form and indicate your institution type. We will respond promptly with appropriate pricing and documentation.

LinguaGraph is compatible with three software options:

• LinguaView — entry-level software for real-time EPG display and recording
• LinguaView 3D — adds a 3D animated tongue-palate model with 360° rotation
• icSpeech Professional Edition — full multiparameter speech analysis platform with EPG displays, biofeedback games, lingual parameters, and simultaneous recording of ultrasound, EGG, nasometry, airflow and video

Developers can also access the LinguaGraph SDK to build custom applications. Contact us for guidance on choosing the right software for your requirements.

Raw EPG data can be exported to CSV (comma-separated values) format using icSpeech Professional Edition. Each row in the CSV file represents an EPG frame, stored as a 64-bit hexadecimal value. A bitmap lookup table is used to extract the individual electrode contact states from each frame.

CSV files can be opened in standard data analysis applications including Microsoft Excel, MATLAB, R, and Python, making the data readily accessible for offline analysis and research.

Contact us for further information on EPG data export, including documentation on the CSV file format.

Ultrasound tongue imaging and electropalatography (EPG) are complementary rather than competing techniques — each captures articulatory information that the other cannot.

Ultrasound shows the shape and movement of the tongue body in real time, including regions that do not contact the palate. It is particularly effective for visualising tongue root position, dorsal gestures, and the full tongue contour in midsagittal view. However, ultrasound cannot directly measure tongue–palate contact.

Electropalatography measures exactly where and when the tongue contacts the hard palate across 62 electrode positions, providing precise, quantifiable contact data. It is particularly effective for sibilant errors, lateral fricatives, and other articulation patterns that midsagittal ultrasound cannot directly capture. Research has shown that lateral fricatives, for example, are easily visualised by EPG but not by midsagittal ultrasound (Cleland et al., 2025).

Both techniques can be used simultaneously using icSpeech Professional Edition, allowing tongue shape and contact patterns to be recorded in a single session.

• ResNet-50 — highest accuracy, lowest speed
• MobileNet V2 1.0 — midrange accuracy and speed (default)
• MobileNet V2 0.35 — lowest accuracy, highest speed

Electroglottography systems range from portable, single-unit instruments to large laboratory workstations, so prices vary widely. The Laryngograph EGG-D200 is a portable, USB-powered system that connects to any Windows laptop or tablet, making it considerably more affordable than laboratory-based electroglottography systems. For current pricing, including software options, please request a quote.

The EGG-D200 behaves as a standard USB audio device, recording speech and Lx on separate channels. To display, analyse and export the full set of electroglottography parameters including fundamental frequency, contact quotient, jitter and shimmer, dedicated software is required: VoiceSuite, icSpeech Professional Edition, or both.

Please note that VoiceSuite activation requires the EGG-D200 to be configured prior to dispatch. If you decide to add VoiceSuite after purchase, the device will need to be returned for activation. We recommend deciding on your software requirements before ordering. To discuss the right option for your work, please get in touch.

No. Electroglottography is a non-invasive technique. Two surface electrodes are placed on the neck, either side of the thyroid cartilage, and secured with an elasticated Velcro strap. Nothing enters the mouth or airway, and the measurement does not interrupt or alter normal speech, making it well tolerated and suitable for repeated measurement with speakers of all ages.

Contact quotient (Qx) is the proportion of each vibratory cycle during which the vocal folds are in contact, expressed as a percentage. It is derived from the Lx waveform by measuring the contact phase against the full cycle. Contact quotient reflects the nature of vocal fold vibration. It tends to be higher in pressed or tense phonation and lower in breathy phonation, making it a useful objective measure for voice research, teaching and therapy.

The terms are often used loosely, but they are not the same thing. Electroglottography measures the changing area of vocal fold contact — the proportion of each cycle during which the folds are in contact. This is the contact quotient. Closed quotient strictly refers to the proportion of the cycle during which the glottis is closed and no air passes, which is a property of glottal airflow rather than contact, and establishing it normally requires inverse filtering or airflow measurement. Because an electroglottograph senses contact and not airflow, contact quotient is the correct term for the measure derived from the Lx waveform.

Jitter and shimmer are measures of the cycle-to-cycle regularity of vocal fold vibration. Jitter is the variation in frequency from one cycle to the next. Shimmer is the variation in amplitude. Both are derived most reliably from sustained vowels, and together they provide an objective record of how regular or irregular the vibration is. VoiceSuite and icSpeech Professional Edition report jitter and shimmer alongside fundamental frequency and contact quotient.

They are complementary, and the EGG-D200 records both at once. A microphone captures the acoustic output, which is shaped by the whole vocal tract and by background noise. Electroglottography measures vocal fold contact directly at the larynx, with a signal largely unaffected by vocal tract resonance or room noise. This makes the Lx waveform a particularly reliable source for fundamental frequency, and gives a clear view of vocal fold contact that the acoustic signal alone cannot provide. Recording speech and Lx together lets you relate the two.

Electroglottography is used to obtain objective measures of vocal fold vibration across a wide range of settings: voice research, phonetics, voice therapy and singing, where the real-time Lx waveform display provides visual feedback. Because it is non-invasive and low-cost, it is also widely used in studies of phonation type, vocal register, and pitch across languages. The EGG-D200 is used by voice clinicians, singing teachers and researchers worldwide.

VoiceSuite and icSpeech Professional Edition currently support Windows 10 and Windows 11 only. The EGG-D200 hardware uses a standard USB connection and is not platform-restricted, but the software requires Windows. Users working in Mac environments may wish to run Windows via Boot Camp or a virtual machine. Please contact us to discuss your setup.

Yes. icSpeech supplies universities, hospitals, and research institutions globally. We provide formal quotations suitable for institutional procurement processes and grant applications. Please use the Request a Quote form and indicate your institution type. We will respond promptly with appropriate pricing and documentation.

The EGG-D200 connects to a local Windows computer and captures EGG data locally. A speech professional, researcher, or trained assistant can operate the system with the speaker present, while a remote clinician or researcher observes via video call. The EGG display can be shared in real time using screen sharing on any standard videoconferencing platform such as Zoom or Microsoft Teams. Recorded EGG data can also be exported and shared for offline review. Please contact us to discuss remote working arrangements.