Earphone housing with integrated tuning features
Custom in-ear monitors (headsets, headphones, earbuds, hearing aids) having improved audio fidelity characteristics and improved manufacturability are constructed by designing a virtual three-dimensional model housing including sound and vent tubes, and equipment mounting receptacles and clips; and fabricating the housing substantially simultaneously or all-in-one-go using, e.g., a 3D printer. The sound and vent tubes comprise features such as inflection points and profile variations that are impossible to construct using traditional subtractive manufacturing processes.
1. A method of forming a housing for an in-ear sound reproduction device, comprising:
obtaining a casting complementary to a user's outer ear canal;
constructing a virtual model of the casting;
positioning a sound tube within the virtual model, a centerline of said sound tube including at least one inflection point;
subtracting the sound tube from the virtual model to create a bored virtual model; and
fabricating a housing for an in-ear sound reproduction device, said housing resembling the bored virtual model and having at least one integrated sound bore formed substantially simultaneously with the housing.
2. The method of claim 1 wherein the housing is a single-piece housing.
3. The method of claim 1 wherein the sound bore has a non-circular profile.
4. The method of claim 1 wherein the sound bore has an increasing profile area.
5. The method of claim 1 wherein the sound bore has a predetermined length.
6. The method of claim 1 wherein the sound bore comprises a socket to accept an output spout of an electroacoustic transducer.
7. The method of claim 1 wherein the sound bore comprises a discontinuous enlargement at one end, a diameter of such discontinuous enlargement equal to an outer diameter of an adapter tube, and a smaller diameter adjacent such discontinuous enlargement equal to an inner diameter of the adapter tube.
8. The method of claim 1 wherein fabricating comprises fusing together voxels of a thermoplastic substance.
9. The method of claim 1 wherein the sound tube is a first sound tube, the method further comprising:
positioning a second sound tube within the virtual model, a centerline of said second sound tube including at least one inflection point;
subtracting the second sound tube from the virtual model to create a doubly-bored virtual model, and wherein
the fabricating operation produces a housing having at least two integrated sound bores corresponding to the first sound tube and the second sound tube.
10. The method of claim 1 , further comprising:
positioning a representation of a sound-reproducing transducer within the virtual model so that an audio outlet of the transducer couples directly to an end of the sound tube; and
adding a clip to the virtual model so that the clip is formed substantially simultaneously with the housing, said clip to hold a sealed electroacoustic transducer module in place against the at least one integrated sound bore in the housing after the housing is fabricated.