Mobile terminal device

A mobile terminal apparatus comprising:

• a casing that houses a microphone and a speaker;
• and
• a cover that is configured to be removably attachable to the casing and that covers a rear surface of the casing that includes an input section of the microphone and an output section of the speaker, wherein:
• the cover includes a gap between the cover and the casing when the cover is attached to the casing;
• the rear surface of the casing includes a recessed section that intersects with a straight line connecting the input section of the microphone and the output section of the speaker;
• the cover includes a protruding section that mates with the recessed section to block the gap;
• and
• the cover is attachable to the casing by moving the cover in the same direction as the mating direction between the recessed section and the protruding section.

A mobile terminal apparatus comprising:

• a casing that houses a microphone and a speaker and that includes a sound hole for the microphone and a sound hole for the speaker, the sound holes being formed in the same direction;
• a cover that is configured to be removably attachable to the casing and that covers a rear surface of the casing that includes the sound hole of the microphone and the sound hole of the speaker, wherein:
• the cover includes a gap between the sound hole of the microphone and the sound hole of the speaker when the cover is attached to the casing;
• the rear surface of the casing includes a recessed section that intersects at least with a straight line connecting the sound hole of the microphone and the sound hole of the speaker;
• the cover includes a protruding section that mates with the recessed section to block the gap;
• and
• the cover is attachable to the casing by moving the cover in the same direction as the mating direction between the recessed section and the protruding section.