"hearing trumpet" meaning in English

{
  "forms": [
    {
      "form": "hearing trumpets",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "hearing trumpet (plural hearing trumpets)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "A trumpet-shaped acoustic device formerly used as a hearing aid."
      ],
      "id": "en-hearing_trumpet-en-noun-zTVo4ECb",
      "links": [
        [
          "acoustic",
          "acoustic"
        ],
        [
          "device",
          "device"
        ],
        [
          "hearing aid",
          "hearing aid"
        ]
      ],
      "raw_glosses": [
        "(historical) A trumpet-shaped acoustic device formerly used as a hearing aid."
      ],
      "tags": [
        "historical"
      ]
    }
  ],
  "word": "hearing trumpet"
}

{
  "forms": [
    {
      "form": "hearing trumpets",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "hearing trumpet (plural hearing trumpets)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with historical senses",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "A trumpet-shaped acoustic device formerly used as a hearing aid."
      ],
      "links": [
        [
          "acoustic",
          "acoustic"
        ],
        [
          "device",
          "device"
        ],
        [
          "hearing aid",
          "hearing aid"
        ]
      ],
      "raw_glosses": [
        "(historical) A trumpet-shaped acoustic device formerly used as a hearing aid."
      ],
      "tags": [
        "historical"
      ]
    }
  ],
  "word": "hearing trumpet"
}