D defs.my
Entry 1 sense Webster, 1913

echo chamber

/ĕk'-ō chām'-bẽr/ · ech·o cham·ber · IPA
01 n. A room with walls that resonate sound, producing audible echoes; it is used especially to create special sound effects in recording music.
  1. 1.
    A room with walls that resonate sound, producing audible echoes; it is used especially to create special sound effects in recording music.(Music, broadcasting)