Sound output device and sound output method
A sound output device includes: a first imparter that imparts first sound characteristics to an input signal; a loudspeaker that outputs a sound based on a signal obtained by impartation of the first sound characteristics to the input signal; a first microphone that receives a sound based on the sound output by the loudspeaker; a determiner that obtains difference characteristics between frequency characteristics of the input signal and frequency characteristics of a signal derived from the sound received by the first microphone, to determine whether the difference characteristics fall within a predetermined range from target sound characteristics; and an instruction indicator that outputs an instruction for output of an alert if a result of the determination by the determiner is negative, and the first imparter corrects the first sound characteristics based on the difference characteristics if a result of the determination by the determiner is positive.
1. A sound output device comprising:
a first imparter configured to impart first sound characteristics to an input signal;
a loudspeaker configured to output a sound based on a signal obtained by impartation of the first sound characteristics to the input signal by the first imparter;
a first microphone configured to receive a sound based on the sound output by the loudspeaker;
a determiner configured to
adjust mid-range frequencies characteristics of a signal derived from the sound received by the first microphone to have the same frequency characteristics as the mid-range frequencies of the input signal,
after the mid-range frequencies characteristics adjustment, obtain difference characteristics between frequency characteristics of the input signal and frequency characteristics of a signal derived from the sound received by the first microphone, and
determine whether a level of frequencies in a low range of the difference characteristics falls within a predetermined range from a level of frequencies in the low range of target difference characteristics; and
an instruction indicator configured to
output an instruction for output of an alert when a result of the determination by the determiner is outside of the predetermined range, and
correct the first sound characteristics based on the difference characteristics when a result of the determination by the determiner is positive within the predetermined range.
2. The sound output device according to claim 1 , wherein
the instruction indicator is configured to output, as the instruction for output of the alert, an instruction to add a voice signal representative of the alert to the signal obtained by impartation of the first sound characteristics to the input signal.
3. The sound output device according to claim 1 , wherein
the input signal is supplied from an external terminal, and
the instruction for output of the alert is output from the instruction indicator to the external terminal.
4. The sound output device according to claim 1 , wherein
the instruction for output of the alert controls an indicator light.
5. The sound output device according to claim 1 , further comprising:
a second microphone configured to receive ambient sound;
a second imparter configured to impart second sound characteristics to a signal derived from the ambient sound received by the second microphone; and
an adder configured to generate a resultant signal by adding together the signal obtained by impartation of the first sound characteristics to the input signal by the first imparter and a signal obtained by impartation of the second sound characteristics to the signal derived from the ambient sound received by the second microphone by the second imparter,
wherein
the second imparter is further configured to correct the second sound characteristics based on the difference characteristics obtained by the determiner, and
the loudspeaker is configured to output the sound based on the resultant signal.
6. The sound output device according to claim 5 , wherein
the adder is further configured to add at least one of a reverse-phase signal of the signal derived from the sound received by the first microphone or a reverse-phase signal of the signal derived from the ambient sound received by the second microphone.
7. A sound output method, comprising the acts of:
imparting first sound characteristics to an input signal;
adjusting mid-range frequencies characteristics of a signal derived from a received sound output based on a signal obtained by impartation of the first sound characteristics to the input signal to have the same frequency characteristics as the mid-range frequencies of the input signal;
after the mid-range frequencies characteristics adjustment, obtaining difference characteristics between frequency characteristics of the input signal and the corrected frequency characteristics;
determining whether a level of frequencies in a low range of the obtained difference characteristics falls within a predetermined range from a level of frequencies in a low range of target difference characteristics;
if outside of predetermined range, outputting an instruction for output of an alert, and
if within the predetermined range, correcting the first sound characteristics based on the difference characteristics.
8. The sound output method according to claim 7 , wherein
the outputting the instruction for output of the alert includes outputting an instruction to add a voice signal representative of the alert to the signal obtained by impartation of the first sound characteristics to the input signal.
9. The sound output method according to claim 7 , wherein
the input signal is supplied from an external terminal, and
the outputting the instruction for output of the alert includes instructing the external terminal to output the alert.
10. The sound output method according to claim 7 , wherein
the outputting the instruction for output of the alert includes controlling an indicator light to output the alert.
11. The sound output method according to claim 7 , further comprising the acts of:
imparting second sound characteristics to a signal derived from a received ambient sound;
correcting the second sound characteristics based on the difference characteristics;
generating a resultant signal by adding together the signal obtained by impartation of the first sound characteristics to the input signal and a signal obtained by impartation of the second sound characteristics to the signal derived from the received ambient sound; and
outputting the resultant signal to the loudspeaker.
12. The sound output method according to claim 11 , wherein
the generating the resultant signal by adding together the signal obtained by impartation of the first sound characteristics to the input signal and the signal obtained by impartation of the second sound characteristics to the signal derived from the received ambient sound includes further adding at least one of a reverse-phase signal of the signal derived from the received sound which was based on the signal obtained by impartation of the first sound characteristics to the input signal, or a reverse-phase signal of the signal derived from the received ambient sound.