Measurements during deuterium-tritium (D-T) experiments in the Joint European Torus (JET) have revealed, for the first time, ion cyclotron emission (ICE) excited by collective instability of fusion α-particles in plasmas with strong ion cyclotron resonance heating. ICE excited by fusion α-particles has also been observed in JET plasmas with pure T neutral beam injection (NBI). These data test several aspects of α-particle confinement physics. ICE spectra from discharges with high power NBI also show evidence of ion hybrid wave excitation by beam ions, relevant to α-channelling.