Patent Application
20140044269
The present invention relates generally to audio devices and, more particularly, to a system for use with headphones.
On a daily basis people are subjected to a variety of noises of varying amplitude, these sources of noise affecting a person's quality of life in a number of ways ranging from simple annoyance to noise induced fatigue and even hearing loss. Common sources of noise include those related to travel, e.g., subway trains, motorcycles, aircraft engine and wind noise, etc., and those related to one's occupation, e.g., factory equipment, chain saws, pneumatic drills, lawn mowers, hedgers, etc.
To help alleviate background noise while providing a source of entertainment, many people listen to music or other audio programming via a set of headphones. Unfortunately, the use of headphones may also lead to problematic, even dangerous situations if the user is unable to hear the various auditory cues and warnings commonly relied upon in day to day living (e.g., warning announcements, sirens, alarms, car horns, barking dogs, etc.). Accordingly, what is needed is a system that provides its users with the benefits associated with headphones without their inherent drawbacks and limitations. The present invention provides such a system.
An intelligent ambient sound environment monitoring system for use with a set of headphones is provided, the system monitoring the user's ambient sound environment and notifying the user whenever there is a critical sound within the background, thus insuring that the user is aware of his or her environment even if the headphones are noise cancelling headphones or are coupled to an iPod®, MP3 player, CD/DVD player, cell phone, computer or other audio source. In order to determine critical background sounds, a processor (e.g. a DSP) within the system compares the ambient sound environment with a preset set of sound characteristics, where critical background sounds are those determined to match the preset set of sound characteristics. Once a critical background sound is identified, an audio notification signal is output to the headphones, where the audio notification signal may be a simple alarm signal (e.g., a beep or other distinctive tone) or may be comprised of the actual, or a portion of the actual, background environment. In systems in which the headphones are coupled to an audio source, the output from the audio source may be temporarily suspended or the volume of the audio source may be temporarily decreased whenever the audio notification signal is output by the ambient sound monitoring system, thus emphasizing the critical background sounds relative to the audio source output.
In one aspect, the preset set of sound characteristics include at least one frequency signature. The frequency signature typically corresponds to a band of audible frequencies, for example a band of frequencies with a band range of 1500 Hz or less. The preset set of sound characteristics may also include sound amplitude in which case the system may be configured to only output the audio notification signal to the headphones if the sound level corresponding to the critical background sounds exceeds the preset sound amplitude. The preset set of sound characteristics may also include sound duration in which case the system may be configured to only output the audio notification signal to the headphones if the time period corresponding to the critical background sounds exceeds the preset sound duration. The various characteristics included in the preset set of sound characteristics may be input using one or more user accessible switches, e.g., push button switches, slide switches, rotary switches, and touch screen soft buttons.
In another aspect of the invention, a method of interjecting ambient background sounds into a set of headphones is provided, the method including the steps of monitoring the user's ambient sound environment, comparing the ambient sound environment to a preset set of sound characteristics, identifying critical background sounds in which the ambient sound environment matches the preset set of sound characteristics, and interjecting at least a portion of the user ambient environment (e.g., the critical background sounds) into the set of headphones whenever critical background sounds are identified. In some instances, the step of interjecting ambient environment into the headphones is only performed when the sound level of the critical background sounds exceeds a preset sound level, or when the period of time corresponding to the critical background sounds exceeds a preset sound duration. The method may additionally include the steps of identifying ambient noise within the user's ambient sound environment and generating a noise cancellation signal in response to the identified ambient noise. The method may additionally include the step of transmitting an audio stream from an audio source over the headphones, where transmission of the audio stream may be temporarily suspended or the volume of the audio stream may be temporarily decreased whenever the system interjects ambient environment into the headphones.
A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.
The present invention overcomes the problems associated with any of a variety of different types of sound isolating headphones by providing an ambient sound monitoring system that allows a user to be aware of select sounds in their environment, sounds that they would otherwise hear if not for the headphones. As used herein, the term “headphones” refers to any of a variety of well-known auditory devices that may be used, for example, to reproduce music or other auditory programming, such devices including, but not limited to, ear buds, in-ear headphones, in-ear monitors, over-the-head headsets/headphones, over-the-ear headsets/headphones, clip-on headsets/headphones and behind-the-neck headsets/headphones. Additionally, and as described further below, the present invention may also be used with sound attenuating headphones and ear plugs, regardless of whether the sound attenuation is due to passive, active or a combination of passive and active noise cancellation.
The sounds received by microphone 101 are processed by sound processor 103 to determine if any of the sounds detected by microphone 101 should be categorized as critical based on a set of predefined criteria. Sounds that are deemed critical are broadcast through headphones 105. Alternately, if a critical sound is detected, the system may be configured to send a warning indicator to the user, for example a series of beeps, thereby signifying to the user that they should remove their headphones so that they may hear the critical sounds.
The present invention may utilize any of a variety of sound recognition algorithms of varying complexity. As sound recognition algorithms are well known by those of skill in the art, a detailed explanation is not provided herein. In the simplest configuration of the invention, once DSP 203 detects a match between the monitored sound and a preset sound signature (step 305), the system performs a preset response such as passing the detected sounds or a notification tone through to the user via headphones 105 (step 307). The detection and monitoring process continues (steps 309 and 311) for as long as the user is utilizing headphones 105; alternately, until the user terminates the monitoring process.
The detection algorithm may utilize a variety of characteristics to identify a preset sound signature from the ambient environment. For example, the system may use both the frequency spectrum and the corresponding sound levels, also referred to as sound amplitudes, to distinguish critical sounds from those of the general background. This is quite similar to the way in which a person will often use sound levels to determine the urgency associated with a particular sound. For example, the volume of an alarm can be used to determine the proximity, and thus the urgency, of an alarm or siren. Similarly, the volume of speech can be used to distinguish general background speech (i.e., background chatter) from speech that may be directed at the listener.
Sound duration is another key metric that may be used by the system to determine if a detected sound should be deemed critical. Sound duration helps the DSP to distinguish between short duration sounds that may match the preset sound signature (e.g., a sneeze) from similar, more important sounds (e.g., flight attendant asking the user a question or providing instructions, an alarm, etc.). This modification of the algorithms of
It will be appreciated that frequency signature, amplitude and duration may be applied in other combinations, and other orders, than those illustrated in
As described above, in general when systems 100/200 determine that the background includes a critical sound of which the listener should be aware, the system can either transmit a notification/alarm signal to the user, or pass the background sound on to the user via headphones 105. In the former case, the notification (i.e., alarm) signal may be a distinctive tone such as a beep, a series of beeps, or some other sound effect that is designed to get the user's attention. The intent of the notification/alarm is to notify the user to look around and be aware of their surroundings, possibly even removing their headphones if deemed necessary. In the alternate case in which the background sound is passed on to the user, the system may be configured in a number of ways. For example, once background sound is determined to be critical, everything that is detected by microphone 101 may be passed through to the user via headphones 105. Alternately, systems 100/200 may use filters to only pass a narrow band of frequencies on to the user, this band including the critical sounds. For example, if the critical sounds are located between 2500 and 3500 Hz, frequencies outside of this range may be filtered out. In an embodiment in which headphones 105 are not just sound attenuating headphones but are instead coupled to an audio source, in a preferred embodiment the system is configured to automatically lower the volume or completely suppress the signal from the audio source when the critical sound is passed through to the user, thus emphasizing the critical sound over the user's audio source. Preferably the length of time that the system passes background sounds through to the user is also configurable. Typically the system is either configured to terminate passage of background sounds to the user after they are no longer deemed critical. Alternately, the system may be configured to pass background sounds to the user for a preset period of time (e.g., 30 seconds, 1 minute, 3 minutes, etc.) after the initial critical event is detected, or after the critical event ceases.
As noted above, various aspects and features of the present invention may be configured to optimize performance for a particular user or segment of users. System configuration may be performed by the manufacturer, thus allowing the manufacturer to offer different models with different capabilities and functionality. Alternately, some or all aspects of the system may be configurable by the user. For example, if the system is integrated into a set of over-the-ear headphones, the user-configurable parameters may be adjusted via any of a variety of switch types (e.g., push buttons, slide switches, rotary switches, etc.) built into one or both headphone earcups. Alternately, the switches used to adjust the user-configurable parameters may be built into a small housing attached to the headphones by a lanyard or integrated into the headphones' audio cable. This latter configuration is especially useful if the headphones are comprised of in-ear headphones or earbuds that may not have sufficient space to accommodate the necessary switches to provide user adjustability. Alternately, the switches used to adjust the user-configurable parameters may be accessible via a software/computer interface, this configuration being useful regardless of whether the processing is not locally, e.g., within the hardware associated with the headphones, or remotely, e.g., a cloud-based system.
It will be appreciated that if the ambient sound monitoring system of the invention is user configurable, or at least partially user configurable, preferably the controls are simplified to promote the user experience. For example, while the user can be presented with various frequency bands for system monitoring (e.g., 1000 to 2000 Hz, 2000 to 3500 Hz, etc.), in at least one embodiment the user is given descriptive terms that may be easier for the user to relate to than different frequencies. Exemplary descriptive terms include “crying baby”, “speech”, “alarm”, “horn”, and “barking dog”. It should be understood that these are just examples of possible terms that may be used to describe different frequency bands or sound signatures that may be of interest for a particular user and/or segment of users. Similarly, critical sound amplitude may be presented to the user in a range from “soft” to “loud” and duration may be presented to the user in a range from “short” to “long”.
In addition to integrating the ambient sound monitoring system of the invention into a set of headphones, either directly or in a housing mounted to a lanyard or the audio cable, the system may also be configured as a separate device. Configuring the system as a separate device with its own housing provides greater flexibility, for example allowing the user to switch the device between multiple headphones or replace a set of headphones without having to replace the ambient sound monitoring system. This embodiment is illustrated in
A stand-alone sound monitoring system such as that shown in
In the systems illustrated in
As previously noted, the ambient sound monitoring system of the present invention is equally applicable to simple sound isolation headphones as well as those that are intended to be coupled to an audio source (e.g., MP3/CD/DVD player, etc.). In the former case the invention may be used with either passive or active sound isolation headphones. If the sound isolation headphones are active, preferably the system of the invention utilizes the same components as those required for the active noise cancellation system, simply modified to also perform the functions of the invention as described in detail above. If, however, the sound isolation headphones are passive, it will be appreciated that the headphones must be modified to include not only a microphone (e.g., microphone 101), but also the necessary processor and related hardware (e.g., an A/D converter, a DSP and a D/A converter) as well as a driver. While either a diaphragm driver or an armature driver may be used, typically the selection is based on the size and weight constraints placed on the system by the type of isolation system. For example, in a typical over-the-ear headphone style there is plenty of space available for integration of the entire ambient sound monitoring system of the invention, including one or more drivers (i.e., typically either one driver per headphone set or one driver per ear). In an earplug design where there is very limited space, the ambient sound monitoring system is typically contained within a housing attached to the earplugs via a lanyard and/or audio cable, with miniature armature drivers preferably being used in the earplugs.
It should be understood that identical element symbols used on multiple figures refer to the same component, or components of equal functionality. Additionally, the accompanying figures are only meant to illustrate, not limit, the scope of the invention and should not be considered to be to scale.
Systems and methods have been described in general terms as an aid to understanding details of the invention. In some instances, well-known structures, materials, and/or operations have not been specifically shown or described in detail to avoid obscuring aspects of the invention. In other instances, specific details have been given in order to provide a thorough understanding of the invention. One skilled in the relevant art will recognize that the invention may be embodied in other specific forms, for example to adapt to a particular system or apparatus or situation or material or component, without departing from the spirit or essential characteristics thereof. Therefore the disclosures and descriptions herein are intended to be illustrative, but not limiting, of the scope of the invention.
