An improved hands-free speaker telephone designed to provide high-quality sound
in a relatively small instrument, while at the same time avoiding acoustic shock
to a user pressing the device too closely to an ear. If a speakerphone is mistaken
for an ordinary portable or cellular phone, or simply out of misguided habit, a
user may intentionally or inadvertently press the speaker against an ear. This
action may subject the ear to an overly-loud audio event if the speaker begins
producing sound, as hands-free speakerphone speakers are typically set to a much
higher volume than those of ordinary phones. The effect, which is sometimes referred
to as 'acoustic shock', is worsened significantly where the user actually succeeds
in sealing the phone around the ear, as commonly (and harmlessly) occurs with standard
(personal) phones. To avoid this undesirable phenomenon, the hands-free speakerphone
is provided with a seal-proof speaker configuration. The seal-proof design includes
various anti-sealing features that may be used individually or in combination.
The anti-sealing features of the present invention include a housing for the hands-free
speakerphone comprising two main parts that fit together to enclose the actual
speaker element. The two housing parts are joined in such a way as to crate a parting
line, or recess running along the exterior of the assembled speakerphone. Sound
ports that permit the sound generated by the speaker element are located along
the parting line, which prevents the user's ear from forming an air-locked cavity
containing them. The speaker ports may also be located on a surface of the speakerphone
that is curved to the extent that forming such a seal would be difficult or impossible.
The ports themselves may be hidden so that the user does not attempt to hold them
to an ear at all. Finally, the sound ports are preferable spaced apart such that
even if the user does so, fewer than all of the speaker ports would be included
in the area the user is attempting to seal to an ear.