Headphone device, signal processing device, and signal processing method

1. A headphone device comprising:

sound reproduction means having a diaphragm for performing sound reproduction based on a sound signal;

sound pickup means for performing a sound pickup operation;

filtering means for applying filtering to a picked-up sound signal, which is obtained based on the sound pickup operation by the sound pickup means, to give a noise-cancelling signal characteristic;

combining means for combining the picked-up sound signal that has undergone filtering by the filtering means, and a listening sound signal which is inputted separately as a sound to be listened to by a user, to generate a sound signal supplied to the sound reproduction means;

abnormality determination means for determining occurrence or non-occurrence of an abnormal sound, based on a result of detecting a level of a sound signal obtained within a sound signal processing system, the sound signal processing system including the filtering means and the combining means and being coupled between the sound pickup means and the sound reproduction means, and

control means for performing a control such that a warning notification is provided, in response to a determination made by the abnormality determination means that an abnormality is present.

2. The headphone device according to claim 1 , wherein:

the abnormality determination means detects the level of the sound signal after performing a control such that the listening sound signal is not supplied to the sound reproduction means.

3. The headphone device according to claim 2 , wherein:

the sound pickup means is provided so as to pick up a sound reproduced by the sound reproduction means, forming a noise cancelling system based on a feedback scheme.

4. The headphone device according to claim 3 , wherein the abnormality determination means

detects, as a reference sound pickup level, a pre-filtering level of the picked-up sound signal that is inputted to the filtering means, after performing a control such that the picked-up sound signal that has undergone filtering by the filtering means is not supplied to the sound reproduction means,

detects, as a level at noise cancellation, the level of the sound signal obtained within the sound signal processing system, after performing a control such that the picked-up sound signal that has undergone filtering by the filtering means is supplied to the sound reproduction means, and

finds a level difference between the level at noise cancellation and the reference sound pickup level, and determines the occurrence or non-occurrence of the abnormal sound based on the level difference.

5. The headphone device according to claim 2 , wherein:

the abnormality determination means determines the occurrence or non-occurrence of the abnormal sound based on a size relationship between the detected level of the sound signal and a preset level.

6. The headphone device according to claim 2 , wherein:

the abnormality determination means detects a pre-filtering level of the picked-up sound signal that is inputted to the filtering means.

7. The headphone device according to claim 2 , wherein:

the abnormality determination means detects a post-filtering level of the picked-up sound signal to which filtering has been applied by the filtering means.

8. The headphone device according to claim 2 , wherein:

the abnormality determination means detects at least a level of a predetermined frequency range of the sound signal, as the level of the sound signal.

9. The headphone device according to claim 8 , wherein:

the abnormality determination means determines the occurrence or non-occurrence of the abnormal sound based on a size relationship between the level of the predetermined frequency range of the sound signal and a preset level.

10. The headphone device according to claim 1 , further comprising:

gain adjusting means for adjusting a gain of a sound signal inserted into the sound signal processing system and supplied to the sound reproduction means; and

control means for controlling the gain adjusting means so that a gain given to the sound signal supplied to the sound reproduction means is reduced, in response to a determination made by the abnormality determination means that an abnormality is present.

11. The headphone device according to claim 1 , wherein:

the filtering means, the combining means, and the abnormality determination means are realized by digital signal processing by a digital signal processor; and

the headphone device further comprises

an A/D converter that converts the picked-up sound signal that is an analog signal obtained based on the sound pickup operation by the sound pickup means, into a digital signal, and supplies the digital signal to the digital signal processor, and

a D/A converter that converts a combined signal obtained by signal processing by the digital signal processor as the combining means, into an analog signal.

12. The headphone device according to claim 11 , wherein:

the digital signal processor performs a restart such that its own settings are reset, in response to a determination result that an abnormality is present which is obtained by a functional operation as the abnormality determination means.

13. A signal processing device comprising:

filtering means for applying filtering to a picked-up sound signal to give a noise-cancelling signal characteristic, in a headphone device including sound reproduction means having a diaphragm for performing sound reproduction based on a sound signal, and sound pickup means for performing a sound pickup operation, the picked-up sound signal being obtained based on the sound pickup operation by the sound pickup means;

combining means for combining the picked-up sound signal that has undergone filtering by the filtering means, and a listening sound signal which is inputted separately as a sound to be listened to by a user, to generate a sound signal supplied to the sound reproduction means of the headphone device;

abnormality determination means for determining occurrence or non-occurrence of an abnormal sound, based on a result of detecting a level of a sound signal obtained within a sound signal processing system, the sound signal processing system including the filtering means and the combining means and being coupled between the sound pickup means and the sound reproduction means; and

display means for displaying information;

control means for performing a control such that, in response to a determination made by the abnormality determination means that an abnormality is present, information to that effect is displayed by the display means.

14. A headphone device comprising:

a sound reproduction unit having a diaphragm which is configured to perform sound reproduction based on a sound signal;

a sound pickup unit configured to perform a sound pickup operation;

a filtering unit configured to apply filtering to a picked-up sound signal, which is obtained based on the sound pickup operation by the sound pickup unit, to give a noise-cancelling signal characteristic;

a combining unit configured to combine the picked-up sound signal that has undergone filtering by the filtering unit, and a listening sound signal which is inputted separately as a sound to be listened to by a user, to generate a sound signal supplied to the sound reproduction unit;

an abnormality determination unit configured to determine occurrence or non-occurrence of an abnormal sound, based on a result of detecting a level of a sound signal obtained within a sound signal processing system, the sound signal processing system including the filtering unit and the combining unit and being coupled between the sound pickup unit and the sound reproduction unit; and

a control unit that controls the provision of a warning notification in response to a determination that an abnormality is present made by the abnormality determination unit.

15. A signal processing device comprising:

a filtering unit configured to apply filtering to a picked-up sound signal to give a noise-cancelling signal characteristic, in a headphone device including a sound reproduction unit having a diaphragm which is configured to perform sound reproduction based on a sound signal, and a sound pickup unit configured to perform a sound pickup operation, the picked-up sound signal being obtained based on the sound pickup operation by the sound pickup unit;

a combining unit configured to combine the picked-up sound signal that has undergone filtering by the filtering unit, and a listening sound signal which is inputted separately as a sound to be listened to by a user, to generate a sound signal supplied to the sound reproduction unit of the headphone device;

an abnormality determination unit configured to determine occurrence or non-occurrence of an abnormal sound, based on a result of detecting a level of a sound signal obtained within a sound signal processing system, the sound signal processing system including the filtering unit and the combining unit and being coupled between the sound pickup unit and the sound reproduction unit; and

a control unit that controls the provision of a warning notification in response to a determination that an abnormality is present made by the abnormality determination unit.