• Product
  • invisity ear prompter

    The invisity ear prompter by Phonak is the smallest in-ear RF receiver in the world and the perfect choice for presenters and performers who require crystal clear audio prompts.

    invisity is completely wireless, sits invisibly inside the ear canal, and weighs just 1.5g. It offers total freedom of movement and is ergonomically designed for day-long wearer comfort.

    Today invisity is used and trusted by broadcasters and filmmakers worldwide.

    Two versions are available:

    invisity 4-channel

    4 channels (7 MHz range). Supplied with invisity remote control (pictured left) for discrete channel flicking. Additional adjustable parameters.

    invisity flex

    1 channel (7 MHz range), programmable via the optional invisity programming unit (IPU) or through a Phonak dealer.

  • Technical
  • A closer look at invisity’s technical specifications.

    fixed or programmable (single or multi), 7MHz band
    Frequency response
    200 Hz – 4500 Hz
    Audio signal output 94 dBSPL measured in a 1.3 cc ear simulator (Volume 1 default setting), 102 dBSPL measured in a 1.3 cc ear simulator (Volume 2 default setting), 
    or adjustable on 4-channel model
    Noise filter squelch
    Sensitivity SINAD >17 dB @ E=3mV/m
    Channel selectivity >50 dB (at 200 kHz channel spacing)
    Antenna magnetic, integral
    Spurious emissions below -57 dBm ERP
    Distortion >5% (depends on volume setting)
    Dimensions 19 x 12 x 12mm (0.74″ x 0.47″ x 0.47″)
    Weight 1.5 g (inc. battery)
    Battery life 13 h (constant reception) using Phonak battery
    Power consumption 3.3 mA
    SNR (signal over noise ratio) approx. 41dB in the AGC @ 1 kHz
  • Transmitters
  • Several transmitter options exist for the invisity listen only earpiece. These include:

    Phonak TX300V

    The TX300V (shown left) is the ideal 9.5-inch transmitter for long range use with Phonak invisity. It features:

    • Frequency range of 150-220 MHz
    • 20 frequency settings
    • 2 adjustable length radials
    • Remote antenna with mounting bracket

    The TX300V is fully programmable, fully resistant to temperature extremes and humidity, and available with PTT (with/without VOX function).


    The inspiro transmitter is a comfortable, belt-worn FM device designed for use over short distances. It is available with a lapel- or face-worn mic, features 40 channels, runs for up to 13 hours, and does not require any frequency allocation.


    EasyLink is a simple yet effective voice transmitter. It features a single Zoom microphone mode, an audio input, and can be held in the hand or hung around the neck.

    In-Ear Receiver FAQ

    This section answers the questions we regularly receive about our invisity ear prompter.

    Note: If the information you require is not shown below, please help us improve this page by sending us your question (we will also email you our reply direct).

    Will rain damage my Phonak earpiece

    An earpiece, by nature, cannot be 100% waterproof. However because Phonak covert radio earpieces are worn fully inside the ear channel they are not usually affected by rain.

    How do I ensure my radio earpiece always stays in the ear?

    Phonak in-ear radio earpieces are designed to fit securely in the ear and do so in the vast majority of cases.

    However, should you want a little extra assurance during covert communication operations, we recommend some useful accessories called SoftWraps to help (see our Accessories section). Simply wrap one or more of these thin and skin-friendly strips around your earpiece to create the perfect fit inside your ear canal.

    Can I use any kind of battery in my earpiece?

    Yes, any brand will work in theory however some non-Phonak batteries do cause problems. To guarantee proper performance we strongly recommend only using Phonak A10 Zinc-Air batteries (article no. 070-0074).

    Is it okay to cut off my earpiece’s nylon feeler?

    Yes, you can remove this feeler (the earpiece’s short transparent stalk) if required, but be aware that this feeler exists for a reason – to help you safely remove the earpiece from your ear. Therefore cutting off the feeler will make it trickier to take out your earpiece.

    If you are worried about discretion, simply bend the feeler to fit it inside the middle section of your outer ear (the ‘concha’).

    Does Phonak offer different sizes of radio earpiece?

    No, we supply one standard size which fits the vast majority of ear canals. If an earpiece is a little too small for your ear canal, we recommend using SoftWraps (article no. 098-3004) to better secure it in the ear.

    Do Phonak radio earpieces suffer from electromagnetical interference (EMI)?

    Our covert radio earpieces are optimized for minimal EMI, especially Phonito Nano. Our Profilo Nano system however is really the ultimate non-interference product as it is the world’s only 100% EMI-free earpiece.

    Why do my earpiece batteries die so quickly?

    This is usually due to incorrect storage. Earpiece batteries should be kept separately (away from each other), as when they are stored in the same pouch or compartment they can short-circuit and lose battery life.

    How do I clean invisity?

    It is important to ensure that invisity is perfectly clean before use. Its green wax guard must be free of wax, as must the openings between the wax guard and the receiver.

    We recomme

    1. Clean invisity’s entire surface and its green Cerumex wax guard with Phonak moist cleansing tissues.
    2. Not using any cleaning tools or strong detergent.
    3. Fitting a new green wax guard when required (i.e. after experiencing sound distortion and/or volume reduction) using the cerumen filter system.
    4. Always checking that the green wax guard is correctly in place before use. 
    5. For more details download our ‘invisity Cleaning Guide’ PDF via the Downloads tab of this page.

    What is invisity’s maximum volume level?

    A maximum of 108 decibels (dB) can be programmed using the invisity Programming Unit (IPU).

    What is invisity’s operating range?

    This very much depends on the signal output power of the transmitter being used and the environment in which you work.

    That said, typical operating ranges for invisity transmitters (in free field) are: 15 – 30m (50 – 100 feet) for inspiro and up to 150m (500 feet) for our Phonak TX-300V transmitter.

    You should always test your transmitter’s operating range ‘in-situ’, before going live, to ensure your invisity system offers the coverage and performance you require.

    Which frequency bands does invisity use?

    It uses 158-188 MHz, 195-202MHz and 214-220MHz. For further details please check with your Phonak supplier.

    My invisity is making a hissing sound – is this normal?

    This type of sound is normal. To eliminate it completely, we recommend using a transmitter with a PTT unit (with or without a VOX function). A range of PTTs are available direct from Phonak.

    What can the invisity remote control change?

    The RC is designed to flick between the pre-programmed channels of our invisity 4-Channel receiver.

    How long does invisity’s battery last?

    If using our recommended Phonak battery, invisity’s typical running time is 13 hours.

    What does zinc-air mean and how should I handle such batteries?

    After you remove the sticker from the bottom of a zinc-air battery, the battery actually runs on air (this enters the battery through the tiny hole and activates it). Be sure to remove the battery’s sticker at least one full minute before inserting the battery into invisity in order to give the battery enough time to reach full power. View/download our Zinc-Air FAQ (PDF).

    Can I fit my system’s wiring loop in a backpack/bag/harness?

    Yes. Phonak does offer individual solutions such as harnesses and vests, but these must be discussed directly with your Phonak Sales representative (locate your nearest supplier here or contact us direct). This especially applies to Profilo Nano wiring loops.

    Can I use a Phonak loop with built-in microphone effectively under thick winter clothes?

    Yes. The microphone is built with covert use in mind, which means it is designed for use under clothes. However very thick garments or body armor etc. may slightly reduce its sensitivity.

    Are Phonak loops available in different colors?

    Yes, Phonak’s covert wiring loops for Profilo Nano and Phonito are all available in beige/pink and black.

    Are different length wiring loops available?

    Yes. Our standard loop length is 65cm (25 inches) and our long loop measures 74cm (29 inches). Just specify which you require when placing your order.

    How should I properly clean and maintain my covert radio earpiece?

    Regular earpiece cleaning and maintenance are key to ensuring your product’s long-term performance and reliability. Here are our Top 4 Maintenance Tips:

    1. Give it a wipe


    To keep your earpiece free from ear wax and external grime (usually transmitted via the fingers), use a damp cloth or Alco wipe to regularly clean your receiver. (Such regular cleaning also vastly reduces the chances of you picking up an ear infection.)

    2. Change the filter

    All Phonak in-ear receivers include a built-in wax filter. Make sure you have a stock of these on hand and change them regularly to avoid sound problems and reduced in-ear volume.

    We recommend checking your earpiece’s filter before each operation. If it is blocked, change it (see the mini User Guide supplied with the filter pack).

    Note: the more you use your earpiece, the more wax your ear will typically produce and therefore the more regularly the wax filter will need to be replaced.

    3. Remove the batteries

    Batteries can leak and the resulting liquid can destroy your earpiece. Therefore always remove your earpiece’s battery when not in use.

    4. Smart storage

    In addition to removing its batteries, keep your earpiece in a safe place (the pouch it arrived in works great). This way you will keep all its accessories and batteries together, and avoid unnecessary dirt building up in and around the earpiece.