Patent Application
20070237334
The present invention generally relates to methods and system for enhancing audio output of computing terminals.
Ambient noise may be problematic for a user of a communication device in a noisy environment (e.g., city street, construction site, delivery truck, etc.). For example, the ambient noise may be combined with speech of the user when communicating with a recipient. The ambient noise distorts and/or degrades a quality of the signal making it difficult for the recipient to decipher the user's speech.
Similarly, when the communication device receives a response message, it may be inaudible and/or unintelligible due to the ambient noise and/or a distance of the user from the communication device (e.g., a far field modality). For example, when utilizing a “speaker-phone” feature, the communication device may be several feet from the user. The distance between the user and the communication device and/or the ambient noise may significantly affect a signal-to-noise ratio at the communication device (e.g., when transmitting) and at the user (e.g., when receiving). Therefore, a method of enhancing output to users of communication devices is currently desired.
The present invention relates to a method and system for enhancing audio output of a computing terminal. The method comprises receiving a signal corresponding to an audible output, receiving an indication of an ambient noise level in an environment into which the audible output will be output, processing the signal based on at least the indication of the ambient noise level to produce a modified signal, and outputting the modified signal.
The present invention may be further understood with reference to the following description and the appended drawings, wherein like elements are provided with the same reference numerals. The present invention discloses a system and method for enhancing an audio output of a computing terminal. An exemplary embodiment of the present invention is described with reference to a mobile computing unit modifying an output signal which includes an audible signal as a function of a level of ambient noise in a current environment of the unit (e.g., as determined from ambient noise in input signals). Those of skill in the art will understand that the present invention may also be implemented in stationary computing terminals, or any other computing device which receives and outputs audible signals.
The user 5 emits a sound 12 which the MU 10 converts into an input signal for transmission to the recipient 20 over the communications network. The MU 10 receives the sound 12 via one or more speakers (e.g., an array of speakers). However, as shown in
As shown in
When the MU 10 is processing the input signal to enhance the quality thereof, the MU 10 may generate processing data corresponding to a level of the ambient noise 30 and/or the signal processing technique(s) used to improve the quality of the signal. The MU 10 may utilize the processing data when modifying the response signal. For example, if the user is working in a loud factory, the data may indicate that the ambient noise level (e.g., a sound pressure level (“SPL”)) is approximately 90 decibels (“dB”). Thus, the MU 10 utilizes the processing data to compensate for the ambient noise 30 (e.g., 90 dB) in the environment of the user 5. Different activities in different environments may generate corresponding SPLs as shown below by the exemplary list:
Referring back to
In one exemplary embodiment, the output signal enhancement technique 24 includes amplifying small return signals, compressing return signals and supplementing them with make-up gain and/or a combination thereof. For example, the response signal may be compressed by a compressor (e.g., a coder/decoder (“CODEC”) chip) utilized by the MU 10. The CODEC chip may be, for example, an 8-bit digital audio converter utilizing a nonlinear quantization scheme known as “mu-law encoding.” However, it will be understood by those of skill in the art that any of a variety of compressors may be used, e.g., those implemented in separate chips or CODECs implemented by the main processor. The amount of compression may be controlled as a function of the processing data. Thus, a dynamic range of the response signal may be reduced and supplemented with make-up gain to reach the level of the ambient noise 30, enabling the user 5 to hear the response 22.
In the exemplary embodiment of
As shown in
The release time is an amount of time which the compressor utilizes to increase the gain 130 when the input signal drops below the threshold. Similar to the attack time, a greater amount of distortion may result as the release time approaches zero. Thus, a release time of approximately several periods of the input signal 110 may be appropriate.
Although the compressor reduces the gain 130 when the input signal 110 is greater than the threshold, a make-up gain may be utilized to supplement the compressed signal 120. The make-up gain may be provided by any number of methods, such as, for example, the compressor including a final gain stage with a level control, adjusting the compressed signal 120 prior to output by the MU 10. In the final gain stage, the signal 120 may be supplemented with the make-up gain before being converted into the output 26 emitted from the MU 10, as shown in
In step 152, the MU 10 receives a signal. In the exemplary embodiment, the signal is the response signal from the recipient 20. The MU 10 may optionally measure the ambient noise level (step 154). In the above examples, it was considered that the ambient noise level was measured when the user 5 spoke into the MU 10. However, according to other exemplary embodiments of the method 150 the ambient noise level is measured subsequent to the MU 10 receiving the response signal and prior to the MU 10 processing the response signal. Thus, it will be understood by those of skill in the art that this step may be performed at various points in time. For example, in one embodiment of the present invention, the MU 10 may measure the ambient noise level prior to performing the signal enhancements 14 on the input signal corresponding to the input 12. That is, the MU 10 may measure the ambient noise level, and process the input signal as a function thereof. Accordingly, the MU 10 may perform the signal enhancements 24 as a function of that ambient noise level. In another embodiment of the present invention, the MU 10 may not measure the ambient noise level at all, as will be discussed below in step 156.
In step 156, the MU 10 processes the response signal. That is, the MU 10 performs the signal enhancements 24 (e.g., compression of the response signal) as shown in
According to another embodiment of the present invention, the MU 10 may process the response signal without measuring the ambient noise level. For example, the MU 10 may perform signal-enhancing techniques on every response signal, thereby ensuring that the output 26 is always of highest quality. Alternatively, the MU 10 may only perform the signal enhancing techniques upon a cue (e.g., activation of a trigger) from the user 5.
In step 158, the modified response signal is output to the user 5. The output 26 emitted from the MU 10 may be entirely intelligible to the user 5, because the lowest response in the dynamic range has been increased to or above the ambient noise level.
An advantage of the present invention is that low level voice signals may be increased over ambient noise without clipping or saturating a speaker. In other words, an increased output level may be provided to a user without forcing the speaker outside of its normal operating limits. Thus, a segment of speech, despite a potentially wide dynamic range including some relatively low SPL signals, may be made entirely audible to a user without damaging the speaker in the user's MU.
The present invention may prove particularly useful where the user 5 is in a far-field modality and the recipient 20 is in a near-field modality. For example, the user 5 may be utilizing a speakerphone feature of the MU 10, perhaps to enable him to rest the MU 10 on a dashboard of a forklift that he is operating in a factory. However, the recipient 20 may be a user communicating through the MU 21 held directly to his ear (e.g., a supervisor in his office giving instructions). Thus, because of a remote location of the MU 10 with respect to the user 5, a greater amount of ambient noise may interfere with input to and output from the MU 10, as compared to an amount of interference at the supervisor's end. However, according to the present invention, the user 5 may hear his supervisor's instructions over the ambient noise from the factory. Further, because the signal transmitted to the supervisor is likely enhanced to reduce noise from the user's 5 end, enhancing the signals provided to the user 5 offers greater symmetry in the communication. Accordingly, both far field users and the near field users are able to communicate more easily and efficiently.
The present invention has been described with reference to the above exemplary embodiments. One skilled in the art would understand that the present invention may also be successfully implemented if modified. Accordingly, various modifications and changes may be made to the embodiments without departing from the broadest spirit and scope of the present invention as set forth in the claims that follow. The specification and drawings, accordingly, should be regarded in an illustrative rather than restrictive sense.
