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An outlined ear with a diagonal bar, usually with a 'T' in the lower-right corner — indicating an assistive listening system, and specifically an induction loop when the T is present.
Also known as: Hearing loop symbol, International Symbol of Access for Hearing Loss, T-loop symbol, Induction loop sign, Ear symbol with a T
Standardised by ISO as an audio-induction-loop symbol in 1986. The ear-with-a-bar outline indicates an assistive listening system is available; adding a 'T' signals specifically that an induction (hearing) loop is installed, so hearing-aid and cochlear-implant users can switch their device to telecoil mode.
Indicates that an assistive listening system is available in the room or venue. When a 'T' appears in the lower-right corner, it indicates specifically that an induction (hearing) loop is installed, and that hearing devices should be switched to telecoil mode.
Contexts: Public information
The International Organization for Standardization created an ISO 7001 symbol for audio induction loops in 1986; a separate IEC standard, IEC 60118-4 (2007), governs the performance of the loop systems themselves rather than the sign.
The 1986 date and the IEC 60118-4 reference come from a hearing-loop manufacturer's own history page — a commercially interested source, though both claims are specific and independently checkable.
1986 onwards · Contexts: Public information
Background colour is conventional rather than definitional: blue is common in the United States, but the symbol's identity rests on the ear-and-bar outline and the presence or absence of the 'T'.
United States (colour convention) · Contexts: Public information
Is an instruction to switch a hearing aid to its T setting, which picks up the loop's magnetic field directly and drops the room out. That is why a loop transforms a ticket window or a church: the wearer hears the microphone rather than the acoustics. Without the T setting selected the loop does nothing at all, and a wearer who does not know the setting exists will conclude the loop is broken.
Contexts: Public information
Is found at counters and ticket offices, in places of worship, theatres, cinemas and council chambers, in taxis, and increasingly on portable units carried to a desk on request rather than installed in the floor.
Contexts: Public information
Related forms that are not treated as separate canonical symbols — see our variant rules.
Assistive listening system (no T)
The same ear-with-a-bar outline without the 'T' indicates an assistive listening system in general — which may be an FM or infrared system rather than an induction loop.
An outline drawing of a human ear with a diagonal bar across it, commonly with a capital letter T in the lower-right corner. The bar does not mean 'no hearing' — the whole mark indicates that assistive listening is available.
Both are public-information accessibility marks and frequently appear together on venue signage, but they indicate different provisions — wheelchair access versus assistive listening.